The Role of Visual Evoked Potentials in the Diagnosis of Optic Nerve Injury as a Result of Mild Head Trauma

The curve of visual evoked potentials was observed and compared with changes of visual acuity and visual field during a 24-month period in a group of 39 patients with optic nerve injury as a result of mild cerebral trauma. Results of the study showed great improvement of visual acuity and visual field after treatment, and slower and continuous improvement of visual evoked potentials. The main abnormality of visual evoked potentials is the shortening of amplitude, which is recorded to gradually recede after treatment in half of the patients. Authors conclude that the shortening of amplitude can be partially explained by the edema and the compression of fibers in the optic canal. Also, they emphasize that in this type of optic nerve injury visual acuity testing is the best indicator of the promptness and scope of the injury, while visual field research presents the best method for following later delicate changes of visual function

Senile Cataract and the Absorption Activity of Cytochrome C Oxidase

The aim of the study was to determine the activity of cytochrome c oxidase in mitochondrial fractions of cataractogenic epithelial cells of lenses of 60 patients (34 females and 26 males). According to clinical criteria patients were divided into three groups: group 1 – patients with senile cataract, group 2 – active smokers with senile cataract, and group 3 – diabetic patients with cataract as diabetic complication. In the extracted lenses we determined the absorption activity of mitochondrial enzyme cytochrome c oxidase. Biochemical researches using the method of Yonetani and Ray13 were applied. We also applied the statistical Student t-test (p < 0.05) and the variance analysis (R. Fisher) with three parameters and Snedecor F distribution (s = p < 0.001). The activity of cytochrome c oxidase in mitochondrial fraction of lens epithelial cells is twice as low in patients who are active smokers than in the non-smoking patients with senile cataract. We measured a significantly different activity of cytochrome c oxidase between active smokers and the non-smoking patients with senile diabetic cataract (tp < 0.05, sp < 0.001). Cigarette smoke decreases the activity of cytochrome c oxidase in mitochondrial fraction of lens epithelial cells. This enzyme is a terminal oxidase in the synthesis of ATPs. We suggest that smoking decreases the synthesis of energy in the lens of cigarette smokers. This emphasizes the significance of giving up smoking in order to preserve the structure and function of the lens

Incentive-Compatible Surveys via Posterior Probabilities

We consider the problem of eliciting truthful responses to a survey question when the respondents share a common prior that the survey planner is agnostic about. The planner would therefore like to have a "universal” mechanism, which would induce honest answers for all possible priors. If the planner also requires a locality condition that ensures that the mechanism payoffs are determined by the respondents' posterior probabilities of the true state of nature, we prove that, under additional smoothness and sensitivity conditions, the payoff in the truth-telling equilibrium must be a logarithmic function of those posterior probabilities. Moreover, the respondents are necessarily ranked according to those probabilities. Finally, we discuss implementation issues

The effect of fibre cell remodelling on the power and optical quality of the lens.

Vertebrate eye lenses are uniquely adapted to form a refractive index gradient (GRIN) for improved acuity, and to grow slowly in size despite constant cell proliferation. The mechanisms behind these adaptations remain poorly understood. We hypothesize that cell compaction contributes to both. To test this notion, we examined the relationship between lens size and shape, refractive characteristics and the cross-sectional areas of constituent fibre cells in mice of different ages. We developed a block-face imaging method to visualize cellular cross sections and found that the cross-sectional areas of fibre cells rose and then decreased over time, with the most significant reduction occurring in denucleating cells in the adult lens cortex, followed by cells in the embryonic nucleus. These findings help reconcile differences between the predictions of lens growth models and empirical data. Biomechanical simulations suggested that compressive forces generated from continuous deposition of fibre cells could contribute to cellular compaction. However, optical measurements revealed that the GRIN did not mirror the pattern of cellular compaction, implying that compaction alone cannot account for GRIN formation and that additional mechanisms are likely to be involved

Surgical Treatment of Uveitis

The results obtained by pars plana vitrectomy in 24 eyes with chronic uveitis, including endogenous intermediate and other types of uveitis, were retrospectively analyzed. Vitrectomy and lensectomy were performed in 8, and vitrectomy alone in 16 eyes. The mean follow-up period was 50 months, and mean patient age 38 years. There were 15 (71.4%) male and 6 (28.6%) female patients. Improvement of visual acuity was achieved in 79% (19), and visual acuity of 0.1 in 58% of eyes. Visual acuity of <0.2, recorded in 14 eyes, was due to optic disc atrophy in 4, cystoid macular edema in 3, macular pucker in 2, vascular obliteration in 2, and chorioretinal scars in 3 eyes. Postoperative complications included cataract in 4, vitreous hemorrhage in 2, glaucoma in 1, and retinal detachment in 3 eyes. Vitrectomy considerably reduced the severity of inflammatory reaction, and allowed reduction or discontinuation of local and systemic steroid therapy

Brachytherapy – Optional Treatment for Choroidal Neovascularization Secondary to Age-Related Macular Degeneration

Age-related macular degeneration (ARMD) presents the main cause of irreversible loss of central vision in older population, due to a progressive neuroretinal damage and damage of retinal pigment epithelium of foveal area. This observation emphasizes the insufficiency of all presently used therapeutic procedures. Therefore, investigation has been conducted at the University Eye Clinic Zagreb for the last three years testing the effects of brachytherapy with direct episcleral application of ruthenium applicators to the posterior pole of the globe. Forty-two patients aged 58–79 were followed for a min. of 12 months. During this period their central visual acuities remained stable. Six patients showed one-line improvement of visual acuity and 8 patients showed no changes. Twenty-one patient lost 1–2 lines of visual acuity and 7 patients lost more than 2 lines. According to this we can conclude that patients treated with brachytherapy showed significantly better results compared to the control subjects, which is very encouraging

Importance of Early Drug Treatment in Prognosis of the Landau-Kleffner Syndrome

An expert team conducted a ten-year survey of eight children with Landau-Kleffner syndrome (LKS) identified among children referred to Polyclinic »SUVAG« in Zagreb because of hearing disturbances. Although LKS is a rare disorder it is extremely important to detect it because early diagnosis and prompt medicinal treatment may improve the prognosis, whereas neglect and late diagnosis result in language disability. Standard diagnostic criteria must be established to enable timely treatment

Estimation of privacy risk through centrality metrics

[EN] Users are not often aware of privacy risks and disclose information in online social networks. They do not consider the audience that will have access to it or the risk that the information continues to spread and may reach an unexpected audience. Moreover, not all users have the same perception of risk. To overcome these issues, we propose a Privacy Risk Score (PRS) that: (1) estimates the reachability of an user¿s sharing action based on the distance between the user and the potential audience; (2) is described in levels to adjust to the risk perception of individuals; (3) does not require the explicit interaction of individuals since it considers information flows; and (4) can be approximated by centrality metrics for scenarios where there is no access to data about information flows. In this case, if there is access to the network structure, the results show that global metrics such as closeness have a high degree of correlation with PRS. Otherwise, local and social centrality metrics based on ego-networks provide a suitable approximation to PRS. The results in real social networks confirm that local and social centrality metrics based on degree perform well in estimating the privacy risk of users.This work is partially supported by the Spanish Government project TIN2014-55206-R and FPI grant BES-2015-074498.Alemany-Bordera, J.; Del Val Noguera, E.; Alberola Oltra, JM.; García-Fornes, A. (2018). Estimation of privacy risk through centrality metrics. Future Generation Computer Systems. 82:63-76. https://doi.org/10.1016/j.future.2017.12.030S63768

Prediction of protein binding sites in protein structures using hidden Markov support vector machine

<p>Abstract</p> <p>Background</p> <p>Predicting the binding sites between two interacting proteins provides important clues to the function of a protein. Recent research on protein binding site prediction has been mainly based on widely known machine learning techniques, such as artificial neural networks, support vector machines, conditional random field, etc. However, the prediction performance is still too low to be used in practice. It is necessary to explore new algorithms, theories and features to further improve the performance.</p> <p>Results</p> <p>In this study, we introduce a novel machine learning model hidden Markov support vector machine for protein binding site prediction. The model treats the protein binding site prediction as a sequential labelling task based on the maximum margin criterion. Common features derived from protein sequences and structures, including protein sequence profile and residue accessible surface area, are used to train hidden Markov support vector machine. When tested on six data sets, the method based on hidden Markov support vector machine shows better performance than some state-of-the-art methods, including artificial neural networks, support vector machines and conditional random field. Furthermore, its running time is several orders of magnitude shorter than that of the compared methods.</p> <p>Conclusion</p> <p>The improved prediction performance and computational efficiency of the method based on hidden Markov support vector machine can be attributed to the following three factors. Firstly, the relation between labels of neighbouring residues is useful for protein binding site prediction. Secondly, the kernel trick is very advantageous to this field. Thirdly, the complexity of the training step for hidden Markov support vector machine is linear with the number of training samples by using the cutting-plane algorithm.</p