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Open access

Olga Pinhasov

Abstract

In the paper, stability of integro-differential equation is studied. The model of testosterone regulation is considered. The model describes an interaction of: the concentration of hormone (GnRH) which will be denoted as x 1, with the concentration of the hormone (LH)-x 2 and the concentration of testosterone (Te)-x 3 and can be written in the form

{x1(t)+b1x1(t)=0,x2(t)+b2x2(t)g1x1(t)=0,x3(t)+b3x3(t)c10teα1(ts)x2(s)ds=0,t0.

The values bi, i = 1, 2, 3 correspond to the respective half-life times of GnRH, LH and Te. The aim of the work is to propose a concept to hold the concentration of testosterone above a corresponding level. In order to achieve this, distributed input control in the form of integral term is used.

Open access

Mohammad Ali Eghbal, Narges Abdoli and Yadollah Azarmi

Summary

Statins are potent cholesterol-lowering drugs that can have serious adverse effects on the muscles and liver. The aim of our in vitro study was to establish the protective effect of coenzyme Q10 (CoQ10, in its optimal dose of 200 μmol L-1) against cytotoxicity induced by atorvastatin, simvastatin, and lovastatin in isolated rat hepatocytes by observing parameters such as cell death, reactive oxygen species formation, lipid peroxidation, mitochondrial membrane potential, and cellular reduced and oxidised glutathione content. Our findings have shown that pretreatment with CoQ10 was effective in reducing the toxic effects of statins in rat hepatocytes. This work demonstrates that the addition of CoQ10 to statin treatment regimens may protect hepatocytes (and also other types of cells) from statin-induced injuries and alleviate their side effects.

Open access

Ksenija Durgo, Ivana Halec, Ivana Šola and Jasna Franekić

Cytotoxic and Genotoxic Effects of the Quercetin/Lanthanum Complex on Human Cervical Carcinoma Cells In Vitro

Quercetin is the main flavonoid in diet with a potential in the treatment of cancer, cardiovascular, and neurodegenerative diseases. Due to its specific planar chemical structure, quercetin readily forms chelates with metal ions. Complexes of bioactive compounds and metal ions such as lanthanum often show strong cytotoxic and antitumour properties. The aim of this study was to compare the genotoxic effects of the quercetin/lanthanum complex on human cervical carcinoma cells with compare it to the effects of free ligands, quercetin, and lanthanum alone. The quercetin/lanthanum complex showed considerable cytotoxicity in the concentration range of (100 to 1000) mmol mL-1 and exposure time of three hours. The complex also induced a dose-dependent pro-oxidative effects and the formation of single-strand and double-strand DNA breaks. Although we obtained promising results on the cell level, future experiments should answer whether the quercetin/lanthanum complex is cancer-specific and stable enough in physiological conditions to make a potential new antitumour drug.

Open access

Masoumeh Khalili, Mohammad Ali Ebrahimzadeh and Yaghoub Safdari

Abstract

Reactive oxygen species (ROS) can lead to haemolysis and eventually to diseases such as thalassemia and sickle cell anaemia. Their action can be counteracted by the antihaemolytic activity of therapeutic agents. The aim of our study was to identify plants that most efficiently counteract ROS-caused haemolysis. From ten plants known for their antioxidant activity (Orobanche orientalis G. Beck, Cucumis melo L., Albizzia julibrissin Durazz, Galium verum L., Scutellaria tournefortii Benth, Crocus caspius Fischer & Meyer, Sambucus ebulus L., Danae racemosa L., Rubus fruticsos L., and Artemisia absinthium L.) we prepared 30 extracts using three extraction methods (percolation, Soxhlet, and ultrasound-assisted extraction) to see whether the extraction method affects antihaemolytic efficiency, and one extraction method (polyphenol extraction) to see how much of this action is phenol-related. Extract antihaemolytic activity was determined in mice red blood cells and compared to that of vitamin C as a known antioxidant. Nine of our extracts were more potent than vitamin C, of which G. verum (aerial parts/percolation) and S. tournefortii (aerial parts/polyphenol) extracts were the most potent, with an IC50 of 1.32 and 2.08 μg mL-1, respectively. Haemolysis inhibition depended on extract concentration and the method of extraction. These plants could provide accessible sources of natural antioxidants to the pharmaceutical industry

Open access

Adrijana Martinac, Siniša Tomić and Mirna Šimičić

New European Commission Regulation on Variations to the Terms of Marketing Authorisation for Medicinal Products and its Impact on Croatian Legislation

Variations introduced to medicinal product documentation must not affect the quality, efficacy, and safety of the product. Croatian Medicinal Products Act and accompanying ordinances are largely aligned with the EU regulations. The EU has now tried to simplify the issue of variations with a new Regulation, creating differences in the definition of and approach to resolving certain types of variations between Croatia and the EU. These differences could hinder the approval procedure for variations in Croatia, particularly for medicines already approved in the EU. Amending the Croatian Ordinance on medicines already authorised in the EU would be one way of maintaining the efficiency of the Croatian regulatory system.

Open access

Edgar Marcial Pimentel and István Nagy

Applications . Materials, 10/3. (2017) 233. https://doi.org/10.3390/ma10030233 [4] Anuja Datta, Abhijeet Sangle, Hardingham N., Cooper C., Kraan M., Ritchie D., Narayan V., Sohini Kar-Narayan: Structure and Thermoelectric Properties of Bi 2−x Sb x Te 3 Nanowires Grown in Flexible Nanoporous Polycarbonate Templates . Materials, 10/5. (2017) 553. https://doi.org/10.3390/ma10050553 [5] Hyun-sik K., Kyu Hyoung Lee, Joonyeon Yoo, Jehun Youn, Jong Wook Roh, Sang-il Kim, Sung Wng Kim: Effect of substitutional Pb Doping on Bipolar and Lattice Thermal Conductivity in

Open access

Karlo Jurica, Natalija Uršulin-Trstenjak, Darija Vukić Lušić, Dražen Lušić and Zdenko Šmit

Ftalati su esteri ftalne kiseline i alifatskih alkohola koji se dodaju u plastične mase da bi se poboljšala njihova mekoća, savitljivost i rastezljivost. Zbog svojih fizičko-kemijskih svojstava ftalati su vrlo mobilni i lako migriraju iz plastičnih proizvoda u prostor koji ih okružuje, pa tako dospijevaju u okoliš te su stoga opasni za čovjeka.

U radu su ukratko opisana svojstva i raspodjela ftalata u okolišu, toksični učinci na ljudsko zdravlje te zakonska regulativa vezana uz maksimalno dopuštene koncentracije ftalata u vodi za piće i u proizvodima namijenjenima dojenčadi, kao i dopušteni dnevni unos u ljudski organizam. Posebna pažnja posvećena je metodama određivanja ftalata u alkoholnim pićima te razinama ftalata s osvrtom na njihovu pojavnost i koncentracije u šljivovici koja se proizvodi u Hrvatskoj. Obuhvaćena je i tematika vezana za ftalate u denaturiranom alkoholu i neregistriranom alkoholu koji se ilegalno stavlja na tržište.

U zaključku su navedene smjernice za učinkoviti nadzor nad putovima izloženosti ljudi ftalatima.

Open access

Blanka Tariba, Zorana Kljaković-Gašpić and Alica Pizent

.pdf Pravilnik o toksinima, metalima, metaloidima te drugim štetnim tvarima koje se mogu nalaziti u hrani [Legislation on toxins, metals, metaloids and other harmful supstances that could be contained in food, in Croatian]. Narodne novine 16/2005. Catarino S, Pimentel I, Curvelo-Garcia AS. Determination of copper in wine by ETAAS using conventional and fast thermal programs: Validation of analytical method. At Spectrosc 2005;25:73-8. Lara R, Cerutti S, Salonia JA, Olsina RA, Martinez LD. Trace element determination of

Open access

Paul Glynn

Axonal Degeneration and Neuropathy Target Esterase

This brief review summarises recent observations which suggest a possible mechanism for organophosphate-induced delayed neuropathy (OPIDN). Neuropathy target esterase (NTE) has been shown to deacylate endoplasmic reticulum (ER) membrane phosphatidylcholine (PtdCho). Raised levels of PtdCho are present in the brains of swiss cheese/NTE mutant Drosophila together with abnormal membrane structures, axonal and dendritic degeneration and neural cell loss. Similar vacuolated pathology is found in the brains of mice with brain-specific deletion of the NTE gene and, in old age, these mice show clinical and histopathological features of neuropathy resembling those in wild-type mice chronically dosed with tri-ortho-cresylphosphate. It is suggested that OPIDN results from the loss of NTE's phospholipase activity which in turn causes ER malfunction and perturbation of axonal transport and glial-axonal interactions.

Open access

Helena Palmgren, Päivi Jalonen and Simo Kaleva

Health Education and Communication in Occupational Health Services in Finland

This article discusses health education and communication in Occupational Health Services (OHS) based on a questionnaire study conducted in Finnish OHS in 2005. The study focused on educational activities carried out by OH professionals and directed at individual employees, work communities and groups, and representatives of client organisations. The questionnaire was sent to 1132 OH professionals - physicians, nurses, physiotherapists and psychologists - working in 130 OHS units, and representing different OHS providers in Finland. 635 respondents (162 physicians, 342 nurses, 96 physiotherapists, 35 psychologists) returned the questionnaire. The overall response rate was 58 %. There were statistically significant differences in educational activities by different professional groups; differences were also related to the length of working experience in OHS. For all OH professionals, individual employees were the primary clients of health education and communication. Education was less often directed at work communities and representatives of client organisations. However, many issues related to health and well-being at work are not within the reach of individual employees. The impact of health education would be more evident if it also reached those organisational stakeholders with discretion in decision-making. Furthermore, OH personnel should pay attention to the social aspect of learning and work more with groups and work communities.