Comparative bioinformatics analysis and abiotic stress responses of expansin proteins in Cucurbitaceae members: watermelon and melon

Protoplasma - Watermelon and melon are members of the Cucurbitaceae family including economically significant crops in the world. The expansin protein family, which is one of the members of the...     

Paraoxonase and arylesterase levels in autoimmune thyroid diseases

Objective: The aim of this study was to evaluate serum paraoxonase-1 (PON1) activity and its association with oxidative stress in autoimmune thyroid disease (AITD).

Methods: A total of 50 patients with AITD, including 25 with Hashimoto's thyroiditis and 25 with Graves’ disease were enrolled. The control group comprised 27 healthy subjects. Blood samples were obtained in the euthyroid period and 3 months after initiation of medical treatment. Serum samples from patients with AITD and the healthy control group were analyzed for basal PON1, salt-stimulated PON1, and arylesterase (ARE) activities, along with lipid hydroperoxide (LOOH) and total free sulfhydryl (–SH) levels.

Results: Serum PON1 activities and –SH levels were significantly lower (P?<?0.001, for each), whereas LOOH levels were significantly higher (P?<?0.001, for each) in patients with AITD, compared to the control group. We observed no significant differences in ARE levels between the patient and healthy control groups (P?>?0.05). PON1 activity was positively correlated with –SH (r?=?0.522, P?<?0.001) and negatively correlated with LOOH (r?=??0.487, P?<?0.001). PON1 phenotype distribution of the subjects was not significantly different among the three groups (P?=?0.961).

Conclusions: Serum PON1 activity is decreased in patients with AITD, and correlated positively with –SH, a well-known antioxidant, and negatively with LOOH, an index of lipid oxidation.     

Cytogenetic analysis of buccal cells from shoeworkers and pathology and anatomy laboratory workers exposed to n-hexane,toluene, methyl ethyl ketone and formaldehyde

People employed in the shoe manufacture and repair industry are at an increased risk for cancer, the strongest evidence being for nasal cancer and leukaemia. A possible causal role for formaldehyde is likely for cancer of the buccal cavity and nasopharynx. Exfoliated buccal cells are good source of tissue for monitoring human exposure to inhaled and ingested occupational and environmental genotoxicants. To assess the cytogenetic damage related to occupational exposure to airborne chemicals during shoe-making and the processes in pathology and anatomy laboratories, the micronuclei (MN) count per 3000 cells was measured in buccal smears from shoe-workers (group I, n = 22) exposed to mainly n-hexane, toluene and methyl ethyl ketone (MEK) and from anatomy and pathology staff (group II, n = 28) exposed to formaldehyde (FA). Eighteen male university staff were used as controls. The mean time-weighted average (TWA) concentrations of n-hexane, toluene and MEK in 10 small shoe workshops were 58.07 p.p.m., 26.62 p.p.m. and 11.39 p.p.m., respectively. The measured air concentrations of FA in the breathing zone of the anatomy and pathology laboratory workers were between 2 and 4 p.p.m. Levels of 2,5-hexadione (2,5-HD) and hippuric acid (HA), metabolic markers of n-hexane and toluene exposure, respectively, were significantly higher in the urine of workers in group I than in control subjects (p < 0.001 and p < 0.01, respectively). The mean (±SD) MN frequencies in buccal mucosa cells from workers in group I, group II and controls were 0.62±0.45%, 0.71±0.56% and 0.33±0.30%, respectively (p < 0.05 and p < 0.05 compared with controls for group I and group II, respectively). The effects of smoking, age and duration of exposure on the frequency of micronucleated buccal cells from workers in all three groups studied were also evaluated. Overall, the results suggest that occupational exposure to organic solvents, mainly n-hexane, toluene, MEK and FA, may cause cytogenetic damage in buccal cells and that use of exfoliated buccal cells seems to be appropriate to measure exposure to organic solvents.     

The effects of Nigella sativa on bile duct ligation induced‐liver injury in rats

Nigella sativa (NS) has been shown to have antioxidant and antiinflammatory activities in different conditions. The goal of this study was to evaluate the effects of NS on cholestatic liver injury in rats. Thirty rats were recruited in the study as follows: Group 1, Bile duct ligation (BDL) (n = 10); Group 2, BDL plus NS (n = 10); and Group 3, Sham (n = 10). Bile duct ligated group received 0.2 mL kg^?1 dose of NS intraperitoneally daily throughout 14 days. Liver damage and cholestasis were determined by the biochemical and the pathologic examination. Data showed a decrease in gamma glutamyl transferase (GGT), alkaline phosphatase (ALP), aspartate aminotransferase (AST), alanine aminotransferase (ALT), and lactate dehydrogenase (LDH) activities of the NS treated rats when compared with BDL group (p < 0.001 for GGT and p < 0.05 for others). The NS treated rats' tissue levels of total oxidant status (TOS), oxidative stress index (OSI), and myeloperoxidase (MPO) were significantly lower than that of the BDL group (p < 0.01 for all). Increases in total antioxidant capacity (TAC) and catalase (CAT) levels were statistically significant in the NS treated rats compared to BDL group (p < 0.01 for both). On the other hand, administration of NS in the rats with biliary obstruction resulted in inhibition of necro‐inflammation. These results indicate that NS exerts a therapeutic effect on cholestatic liver injury in bile duct ligated rats possibly through attenuation of enhanced neutrophil infiltration and oxidative stress in the liver tissue. Copyright © 2009 John Wiley & Sons, Ltd.     

On the mode of inhibition of eukaryotic protein synthesis by ADP-ribosylation of elongation factor 2

The exchange of free guanine nucleotides with guanine nucleotides bound to elongation factor 2 (EF-2) and to the EF-2-ribosome complex, and the effect of ADP-ribosylation of the EF-2 thereon, were investigated by nitrocellulose filter assay. Under the experimental conditions, stoichiometric amounts of guanine nucleotides were bound, in particular, to ternary complexes of EF-2 with biphasic kinetics. The exchange kinetics were similarly biphasic in all cases. Ribosomes appeared to have variable effects on the exchange kinetics, depending on the type of nucleotide bound. Thus, in their presence, the rate and magnitude of the fast exchange of nucleotides revealed increasing values in the order GTP (GXP) > GTP gamma S > GDP. ADP-ribosylation had no inhibitory effect on the binding of guanine nucleotides to EF-2 or to the EF-2-ribosome complex but reduced significantly the fast exchange of GTP (GXP) and GTP gamma S bound to the EF-2-ribosome complex. The effect of ADP-ribosylation on the fast exchange of GDP in binary and ternary complexes was less pronounced. The mechanism of inhibition of protein synthesis by ADP-ribosylation of EF-2 is discussed in view of these data.     

Alterations of oxidative-antioxidative status in human cutaneous leishmaniasis

Enhanced lipid peroxidation and decreased antioxidant defences have been defined in several diseases. In the present study, we aimed to evaluate the oxidative-antioxidative status of patients with cutaneous leishmaniasis (CL). Concentrations of erythrocyte lipid peroxidation (LPO), as an indicator for the oxidative status, reduced glutathione (GSH), glutathione peroxidase (GSH-Px) and serum vitamin C levels, as indicators for the antioxidative status, were measured. Seventy patients aged between 15 and 50 years (38 patients had active CL and 32 patients had healed CL) and 40 healthy controls aged between 19 and 50 years were included in the study. LPO and GSH of the patients with active CL were significantly higher (p < 0.001), whereas erythrocyte GSH-Px and serum vitamin C levels were lower (p < 0.001, p < 0.01 respectively) than those of healthy controls. There was a significant inverse correlation between LPO and serum vitamin C level (r=-0.32, p < 0.05) in active CL. No significant correlation of LPO, GSH, GSH-Px and serum vitamin C levels in control groups or in the group with healed CL was detected. In the light of our findings it is possible to conclude that patients having CL are affected by oxidative stress, which most likely induces the endogenous antioxidant system. An imbalance between the oxidant and antioxidant systems occurs and the suppressed antioxidants and increased lipid peroxidation may contribute to the progression of the disease.     

Three acylated flavone glycosides from Sideritis ozturkii Aytac & Aksoy

From the aerial parts of Sideritis ozturkii, three new flavonoids, chrysoeriol 7-O-[2'-O-caffeoyl-O-acetyl-beta-D-glucopyranosyl-(1-->2)-beta-D-glucopyranoside], chrysoeriol 7-O[2'-O-caffeoyl-beta-D-glucopyranosyl-(1 -->2)-beta-D-glucopyranoside] and chrysoeriol 7-O[2'-O-p-coumaroyl-6'-beta-O-acetyl-D-glucopyranosyl-(1-->2)-beta-D-glucopyranoside] named as ozturkosides A, B and C, respectively, were isolated, along with three known phenylethanoid glycosides, verbascoside, leucoseptoside A, martynoside and five known diterpenoids, 7-epicandicandiol, linearol, sidol, sideroxol, epoxyisolinearol. The structures were elucidated mainly by spectroscopic methods.