Age-related declines in motion perception have been well documented. We investigated the impact of age on electrophysiological correlates of motion perception, namely the P1 and N2 components of motion onset visual evoked potentials (MO-VEPs). Additionally, we used a model of response times based on the diffusion model to pinpoint the cognitive processes affected by aging. Twelve healthy adults (age (55years) and 19 elderly (age )55years) performed a motion direction discrimination task during EEG recording. Behaviorally, younger and older participants had similar, high accuracy rates - 98% correct, but older adults exhibited 85ms longer response times. Fitting behavioral results with a diffusion model revealed differences between young adults and elderly in non-decision time, which we argue reflects an early perceptual stage. Electrophysiologically, aging effects were present at MO-VEPs P1 and N2 components at the posterior sites. For the P1 component, older as compared to younger adults showed greater topographical voltage distribution. For the N2 component of elderly as compared to young adults we found delayed onsets and diminished amplitudes. We did not find any significant correlations between behavioral and MO-VEP measures. However, regression analysis showed that N2 amplitude and latency were significant age predictors. Overall, our results indicate that in motion perception, age-related changes occur in early stages of visual processing, most likely in striate and extrastriate visual cortices.
COBISS.SI-ID: 30760921
In this study the role of oxidative stress in schizophrenia was investigated by evaluating the relationship of oxidative stress markers with neurochemistry, psychopathology, and extrapyramidal symptoms. Antioxidant activity of superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, and concentrations of malondialdehyde, protein carbonyls, nitrite, nitrate, glutathione, dopamine, noradrenaline, adrenaline,and serotonin were measured in 52 outpatients with DSM-IV diagnosis of schizophrenia treated with haloperidol decanoate. Psychopathology and extrapyramidal symptoms were assessed by positive and negative syndrome scale, global assessment of functioning, abnormal involuntary movement scale, Simpson Angus scale, and Barnes akathisia rating scale. Haloperidol dose was positively correlated with plasma protein carbonyls. Longer duration of illness was associated with decreased levels of glutathione peroxidase. Increased activity of superoxide dismutase was associated with increased levels of catalase, glutathione peroxidase, glutathione reductase and reduced glutathione, and decreased concentration of malondialdehyde, indicating joint action of various antioxidative systems. Increased levels of nitrite and nor adrenaline were associated with decreased level of malondialdehyde. Akathisia was greater in patients with decreased catalase activity, indicating involvement of impaired antioxidant defense in developing extrapyramidal symptoms. These results confirm the hypothesis that oxidative stress is involved in pathophysiology of schizophrenia and severity of extrapyramidal symptoms.
COBISS.SI-ID: 3507825
The DNA genome of a novel HPV genotype, HPV-125, isolated from a hand wart of an immuno-competent 19-year old male was fully cloned, sequenced and characterized. The full genome of HPV-125 is 7,809-bp in length with a GC content of 46.4%. By comparing the nucleotide sequence of the complete L1 gene, HPV-125 is phylogenetically placed within cutaneotrophic species 2 of Alphapapillomaviruses, and is most closely related to HPV-3 and HPV-28. HPV-125 has a typical genomic organization of Alphapapillomaviruses and contains genes coding for five early proteins, E6, E7, E1, E2 and E4 and two late capsid proteins, L1 and L2. The genome contains two non-coding regions: the first located between the L1 and E6 genes (nucleotide positions 7,137–7,809, length 673-bp) and the second between genes E2 and L2 (nucleotide positions 3,757–4,216, length 460-bp). The E6 protein of HPV-125 contains two regular zinc-binding domains at amino acid positions 29 and 102, whereas the E7 protein exhibits one such domain at position 50. HPV-125 lacks the regular pRb-binding core sequence within its E7 protein. In order to assess the tissue predilection and clinical significance of HPV-125, a quantitative type-specific real-time PCR was developed. The 95% limit-of-detection of the assay was 2.5 copies per reaction (range 1.7–5.7) and the intra- and inter-assay coefficients of variation were 0.47 and 2.00 for 100 copies per reaction, and 1.15 and 2.15 for 10 copies per reaction, respectively. Testing of a representative collection of HPV-associated mucosal and cutaneous benign and malignant neoplasms and hair follicles (a total of 601 samples) showed that HPV-125 is a relatively rare HPV genotype, with cutaneous tropism etiologically linked with sporadic cases of common warts.
COBISS.SI-ID: 28776665