Reptile Ownership in Balkan Countries: Demographics and Reliance on Veterinary Advice

The objective of the research was to determine the profile of reptile owners (n = 238) in terms of their socio-demographic characteristics and evaluations of veterinarians’ expertise. Reptile owners living in four non-EU Balkan countries (Bosnia and Herzegovina, Macedonia, Montenegro, and Serbia) were randomly selected from two social networks. Statistically significant differences were found in snake, lizard, and turtle owners (p < 0.05) in terms of gender, employment status, and monthly earnings. Male owners of reptiles were slightly more numerous (52%) compared with female owners (48%). Sixty-four percent of reptile owners were over 20 years old. The unemployed reptile owners (16%) were about five times fewer in number compared with those who studied at university and those who were employed. Forty-one percent of reptile owners declared high monthly incomes. Forty percent of reptile owners never contacted and had no experience with veterinarians. Fifty-eight percent of reptile owners contacted or visited veterinarians due to the medical condition of their animals, 14% of them contacted veterinarians for advice on reptile keeping, and only 6% did so for a preventive veterinary examination. Forty-seven percent of reptile owners were satisfied with veterinary services. The importance of the results of this survey is that they can provide a basis for adopting legislation on the ownership of reptiles as pet animals, together with being a baseline for monitoring subsequent changes in interest in these animals as pets. The results also identify the need for more dedication from veterinarians in educating reptile owners, and for necessary adjustments in veterinary education.     

MAPK/ERK pathway inhibition is a promising treatment target for adrenocortical tumors

Unraveling molecular mechanisms that regulate tumor development and proliferation is of the utmost importance in the quest to decrease the high mortality rate of adrenocortical carcinomas (ACC). Our aim was to evaluate the role of two of the mitogen-activated protein kinase (MAPK) signaling pathways (extracellular signal-regulated protein kinases [ERKs 1/2] and p38) in the adrenocortical tumorigenesis, as well as the therapeutic potential of MAPK/ERK inhibition. ERKs 1/2 and p38 activation were evaluated in incidentalomas (INC; n = 10), benign Cushing's syndrome (BCS; n = 12), malignant Cushing's syndrome (MCS; n = 6) and normal adrenal glands (NAG; 8). ACC cell line (H295R) was used to evaluate the ability of PD184352 (0.1, 1, and 10 µM), a specific MEK-MAPK-ERK pathway inhibitor, to modulate cell proliferation, viability, metabolism, and steroidogenesis. ERKs 1/2 activation was significantly higher in MCS (2.83 ± 0.17) compared with NAG (1.00 ± 0.19 “arbitrary units”), INC (1.20 ± 0.13) and BCS (2.09 ± 0.09). Phospho-p38 expression was absent in all the MCS analyzed. MAPK/ERK kinase (MEK) inhibition with PD184352 significantly decreased proliferation as well as steroidogenesis and also increased the redox state of the H295R cells. This data suggests that MEK-MAPK-ERK signaling has a role in adrenocortical tumorigenesis that could be potentially used as a diagnostic marker for malignancy and targeted treatment in ACC.     

Interactions of 2,6-substituted purines with purine nucleoside phosphorylase from Helicobacter pylori in solution and in the crystal,and the effects of these compounds on cell cultures of this bacterium

Helicobacter pylori represents a global health threat with around 50% of the world population infected. Due to the increasing number of antibiotic-resistant strains, new strategies for eradication of H. pylori are needed. In this study, we suggest purine nucleoside phosphorylase (PNP) as a possible new drug target, by characterising its interactions with 2- and/or 6-substituted purines as well as the effect of these compounds on bacterial growth. Inhibition constants are in the micromolar range, the lowest being that of 6-benzylthio-2-chloropurine. This compound also inhibits H. pylori 26695 growth at the lowest concentration. X-ray structures of the complexes of PNP with the investigated compounds allowed the identification of interactions of inhibitors in the enzyme’s base-binding site and the suggestion of structures that could bind to the enzyme more tightly. Our findings prove the potential of PNP inhibitors in the design of drugs against H. pylori.     

Role of brefeldin A-dependent ADP-ribosylation in the control of intracellular membrane transport

The fungal toxin brefeldin A (BFA) dissociates coat proteins from Golgi membranes, causes the rapid disassembly of the Golgi complex and potently stimulates the ADP-ribosylation of two cytosolic proteins of 38 and 50 kDa. These proteins have been identified as the glycolytic enzyme glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and a novel guanine nucleotide binding protein (BARS-50), respectively. The role of ADP-ribosylation in mediating the effects of BFA on the structure and function of the Golgi complex was analyzed by several approaches including the use of selective pharmacological blockers of the reaction and the use of ADP-ribosylated cytosol and/or enriched preparations of the BFA-induced ADP-ribosylation substrates, GAPDH and BARS-50.A series of blockers of the BFA-dependent ADP-ribosylation reaction identified in our laboratory inhibited the effects of BFA on Golgi morphology and, with similar potency, the ADP-ribosylation of BARS-50 and GAPDH. In permeabilized RBL cells, the BFA-dependent disassembly of the Golgi complex required NAD+ and cytosol. Cytosol that had been previously ADP-ribosylated (namely, it contained ADP-ribosylated GAPDH and BARS-50), was instead sufficient to sustain the Golgi disassembly induced by BFA.Taken together, these results indicate that an ADP-ribosylation reaction is part of the mechanism of action of BFA and it might intervene in the control of the structure and function of the Golgi complex.