Vladan Bajic

Chromosome instability in Alzheimer’s disease (AD) neurons has been previously reported. This pilot study aimed to establish a quantitative technique for assessing X chromosome centromere signals using fluorescence in situ hybridization (FISH). Hippocampal brain tissue was collected at autopsy from sporadic AD patients and age-and gender-matched controls. FISH was utilized to detect and measure the intensity of hybridization signals for X chromosome centromeres in the interphase nuclei of hippocampal brain cells. The premature centromere division (PCD) phenomenon, marked by a close bipartite signal appearing as two separated FISH spots, was examined to see if the hybridized DNA amount in each spot matched the expected centromere DNA amount. The technique effectively distinguished between PCD+ and PCD- signals. The average frequency of PCD,X in the AD group was 7 ± 1%, compared to 3.2 ± 0.84% in controls. This quantitative approach supports qualitative analyses of FISH centromere spots, reinforcing findings of chromosomal instability in AD. The presence of a double signal at the centromere of a single X chromosome indicates re-entered cell cycles, DNA replication, and PCD in hippocampal neurons. This technique provides a reliable method for identifying PCD + signals and contributes to understanding chromosomal instability in AD.

More than 30 types of amyloids are linked to close to 50 diseases in humans, the most prominent being Alzheimer’s disease (AD). AD is brain-related local amyloidosis, while another amyloidosis, such as AA amyloidosis, tends to be more systemic. Therefore, we need to know more about the biological entities’ influencing these amyloidosis processes. However, there is currently no support system developed specifically to handle this extraordinarily complex and demanding task. To acquire a systematic view of amyloidosis and how this may be relevant to the brain and other organs, we needed a means to explore "amyloid network systems" that may underly processes that leads to an amyloid-related disease. In this regard, we developed the DES-Amyloidoses knowledgebase (KB) to obtain fast and relevant information regarding the biological network related to amyloid proteins/peptides and amyloid-related diseases. This KB contains information obtained through text and data mining of available scientific literature and other public repositories. The information compiled into the DES-Amyloidoses system based on 19 topic-specific dictionaries resulted in 796,409 associations between terms from these dictionaries. Users can explore this information through various options, including enriched concepts, enriched pairs, and semantic similarity. We show the usefulness of the KB using an example focused on inflammasome-amyloid associations. To our knowledge, this is the only KB dedicated to human amyloid-related diseases derived primarily through literature text mining and complemented by data mining that provides a novel way of exploring information relevant to amyloidoses.

Increased levels of oxidative stress and oxidative DNA damage are common features in the pathology of Alzheimer's disease (AD) found in neurons and peripheral cells like peripheral blood lymphocytes (PBL). Natural products such as strawberry cultivar Alba are an important source of bioactive nutrients that could help in lowering both the oxidative stress and DNA damage levels. The objective was to estimate the effects of Alba extract on DNA damage in peripheral blood lymphocytes of sporadic AD (aged 60-84 years) patients, and healthy elderly (aged 69-83 years) and young (aged 21-30 years) individuals in in vitro conditions. Comet assay was used as a sensitive technique for the evaluation of PBL DNA damage levels. Reduction of basal DNA damage level in PBL was shown in the young group after the incubation with Alba extract ranging from 25 to 200 μg/ml, with 100 μg/ml being the most effective concentration. Selected Alba extract of 100 μg/ml was further used for PBL treatment of AD and healthy elderly age matched group, displaying potential to significantly attenuate DNA damage levels in both groups (p < .05). Alba extract displayed biological activity against oxidative DNA damage, suggesting that its functional ingredients may have beneficial health effects. PRACTICAL APPLICATIONS: The data obtained in this preliminary study displayed that strawberry Alba extract is efficient against DNA damage induced by endogenous and exogenous oxidative stress in peripheral blood lymphocytes of Alzheimer`s disease in vitro. An active area of future research of Alba cultivar should be to determine the trials in in vivo systems. Our findings also suggest that Alba cultivar's functional ingredients potentially may have beneficial health effects in AD.

Does Alzheimer Disease show a decline in cognitive functions that relate to the awareness of external reality? In this paper, we will propose a perspective that patients with increasing symptoms of AD show a change in the awareness of subjective versus objective representative axis of reality thus consequently move to a more internal like perception of reality. This paradigm shift suggests that new insights into the dynamicity of the conscious representation of reality in the AD brain may give us new clues to the very early signs of memory and self-awareness impairment that originates from, in our view the microtubules. Dialog between Adso and William, in Umberto Eco’s The Name of the Rose, Third Day: Vespers. “But how does it happen,” I said with admiration, “that you were able to solve the mystery of the library looking at it from the outside, and you were unable to solve it when you were inside?” “Thus, God knows the world, because He conceived it in His mind, as if it was from the outside, before it was created, and we do not know its rule, because we live inside it, having found it already made.”

Strawberry fruit Fragaria × ananassa Duchesne, Rosaceae (cv. Romina), rich in anthocyanin polyphenols, has been demonstrated to have favorable effects on health due to its antioxidant properties. The present study investigated the antigenotoxic potential of anthocyanin enriched fraction of Romina strawberry methanolic extract (ACY) against DNA damage on human peripheral blood leukocytes, induced by hydrogen peroxide in vitro. Five concentrations of the ACY extract were used in all experiments (2.5, 5, 10, 15, 20 µg/ml). The results of the alkaline comet assay showed no genotoxic effect of the ACY. After the pre-exposure of the leukocytes to the ACY, and subsequent incubation with H2O2, a decreased number of DNA damaged cells was recorded in all the tested concentrations, compared to controls. In the posttreatment, there was a concentration-dependent DNA damage reduction, while a statistically significant decrease was achieved with 15 and 20 µg/ml concentrations. The results indicate that ACY is efficient in oxidative DNA damage reduction, and it is more potent as a post-applicative than a protective agent.

Gastroesophageal Reflux Disease (GERD) is characterized by acid and bile reflux in the distal oesophagus, and this may cause the development of reflux esophagitis and Barrett’s oesophagus (BE). The natural histological course of untreated BE is non-dysplastic or benign BE (ND), then lowgrade (LGD) and High-Grade Dysplastic (HGD) BE, with the expected increase in malignancy transfer to oesophagal adenocarcinoma (EAC). The gold standard for BE diagnostics involves high-resolution white-light endoscopy, followed by uniform endoscopy findings description (Prague classification) with biopsy performance according to Seattle protocol. The medical treatment of GERD and BE includes the use of proton pump inhibitors (PPIs) regarding symptoms control. It is noteworthy that long-term use of PPIs increases gastrin level, which can contribute to transfer from BE to EAC, as a result of its effects on the proliferation of BE epithelium. Endoscopy treatment includes a wide range of resection and ablative techniques, such as radio-frequency ablation (RFA), often concomitantly used in everyday endoscopy practice (multimodal therapy). RFA promotes mucosal necrosis of treated oesophagal region via high-frequency energy. Laparoscopic surgery, partial or total fundoplication, is reserved for PPIs and endoscopy indolent patients or in those with progressive disease. This review aims to explain distinct effects of PPIs and RFA modalities, illuminate certain aspects of molecular mechanisms involved, as well as the effects of their concomitant use regarding the treatment of BE and prevention of its transfer to EAC.

Alzheimer’s disease (AD) is a neurodegenerative disease that affects millions of individuals worldwide and can occur relatively early or later in life. It is well known that genetic components, such as the amyloid precursor protein gene on chromosome 21, are fundamental in early-onset AD (EOAD). To date, however, only the apolipoprotein E4 (ApoE4) gene has been proved to be a genetic risk factor for late-onset AD (LOAD). In recent years, despite the hypothesis that many additional unidentified genes are likely to play a role in AD development, it is surprising that additional gene polymorphisms associated with LOAD have failed to come to light. In this review, we examine the role of X chromosome epigenetics and, based upon GWAS studies, the PCDHX11 gene. Furthermore, we explore other genetic risk factors of AD that involve X-chromosome epigenetics.

Objective. Inosine 5'-monophosphate dehydrogenase (IMPDH) activity in cancer cells is increased. Tiazofurin selectively inhibits the activity of IMPDH, and it has been granted for the treatment of different cancers and new viral diseases. Its widespread use was limited because exposure to tiazofurin under certain circumstances was found to have a higher frequency of severe non-hematologic toxicity. Therefore, the objective of this study was to examine genotoxic action and inducement of DNA damage of tiazofurin using the comet assay. Methods. The ability of tiazofurin to induce DNA damage was evaluated using single-cell gel electrophoresis (SCGE) technique/comet assay. Human whole blood cells were exposed to three final concentrations of tiazofurin (1µM/mL, 2 µM/mL, and 5 µM/mL) for 30 min in vitro. Results. Our results indicate that tiazofurin produced a significant level of DNA damage on whole blood cells after 30 min of exposure vs. control. All tested concentrations were significantly comet-forming, in a concentration-dependent manner. Conclusion. Our investigation on the tiazofurin-treated cells and their relationship to the formation of DNA damage demonstrated that the genotoxic effect was induced after exposure to tiazofurin under described conditions.

Oxidative stress and inflammation are DNA instability factors for rheumatoid arthritis (RA) patients. The aims of this study were to evaluate cytogenetic alterations in Peripheral Blood Lymphocytes (PBL) in two groups of RA patients: the early and the long-term RA group; and to examine potential of concomitant treatment with Methotrexate (MTX) and Dry olive leaf extract (DOLE) against cytogenetic damage in RA patients after a 3-weeks treatment. A total of 32 RA patients and 10healthy individuals were included. RA patients were equally divided into four groups: two groups with early phase RA (one treated with MTX alone, the other in combination with DOLE); and two long-term phase RA groups (group with active disease and group with low disease activity)-both treated with MTX and DOLE combination. PBL cultures were screened for chromosome aberrations and micronuclei frequencies. Significantly increased frequencies of micronuclei were shown in active phase RA disease (both early and long-term) but not in the group with low disease activity, as compared to controls. Chromosome aberrations were detected for all 4 RA groups. The highest frequencies of micronuclei and chromosome aberrations were found in the long-termactive RA group. After 3 weeks-treatment, there were no significant decrease of the micronuclei frequencies compared to baseline, although they were reduced in all RA groups, except for the group with the long-term active disease. High level of cytogenetic damage in RA patients was concordant with duration and activity of the RA disease. At 3 weeks of therapy, neither the combined treatment (MTX+DOLE), nor MTX alone did not affect the frequency of micronuclei formation.