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Öğe Challenge of human Jurkat T-cells with the adenylate cyclase activator forskolin elicits major changes in cAMP phosphodiesterase (PDE) expression by up-regulating PDE3 and inducing PDE4D1 and PDE4D2 splice variants as well as down-regulating a novel PDE4A splice variant(Portland Press, 1997) Erdogan, S; Houslay, MDThe cAMP phosphodiesterase (PDE) 3 and PDE4 isoforms provide the major cAMP-hydrolysing PDE activities in Jurkat T-cells, with additional contributions from the PDE1 and PDE2 isoforms. Challenge of cells with the adenylate cyclase activator forskolin led to a rapid: albeit transient, increase in PDE3 activity occurring over the first 45 min, followed by a sustained increase in PDE3 activity which began after similar to 3 h and continued for at least 24 h. Only this second phase of increase in PDE3 activity was blocked by the transcriptional inhibitor actinomycin D. After similar to 3 h of exposure to forskolin, PDE4 activity had increased, via a process that could be inhibited by actinomycin D, and it remained elevated for at least a 24 h period. Such actions of forskolin were mimicked by cholera toxin and 8-bromo-cAMP. Forskolin increased intracellular cAMP concentrations in a time-dependent fashion and its action was enhanced when PDE induction was blocked with actinomycin D. Reverse transcription (RT)-PCR analysis, using generic primers designed to detect transcripts representing enzymically active products of the four PDE4 genes, identified transcripts for PDE4A and PDE4D but not for PDE4B or PDE4C in untreated Jurkat T-cells. Forskolin treatment did not induce transcripts for either PDE4B or PDE4C; however, it reduced the RT-PCR signal for PDE4A transcripts and markedly enhanced that for PDE4D transcripts. Using RT-PCR primers for PDE4 splice variants, a weak signal for PDE4D1 was evident in control cells whereas, in forskolin-treated cells, clear signals for both PDE4D1 and PDE4D2 were detected. RT-PCR analysis of the PDE4A species indicated that it was not the PDE4A isoform PDE-46 (PDE4A4B). Immunoblotting of control cells for PDE4 forms identified a single PDE4A species of similar to 118 kDa, which migrated distinctly from the PDE4A4B isoform PDE-46, with immunoprecipitation analyses showing that it provided all of the PDE4 activity in control cells. Forskolin treatment led to a marked decrease of this novel PDE4A species and allowed the detection of a strong signal for an similar to 67 kDa PDE4D species, suggested to be PDE4D1, but did not induce PDE4B and PDE4C isoforms. Elevation of intracellular cAMP concentrations in Jurkat T-cells thus exerts a highly selective effect on the transcriptional activity of the genes encoding the various PDE4 isoforms. This leads to the down-regulation of a novel PDE4A splice variant and the induction of PDE4D1 and PDE4D2 splice variants, leading to a net increase in the total PDE4 activity of Jurkat T-cells.Öğe Comparison of selected toxic elements in cow serum and milk samples from industrial and rural regions(Springer-Verlag, 2004) Erdogan, S; Celik, S; Erdogan, Z[Abstract Not Available]Öğe Effect of different dietary levels of Yucca schidigera powder on the performance, blood parameters and egg yolk cholesterol of laying quails(Blackwell Verlag Gmbh, 2003) Kaya, S; Erdogan, Z; Erdogan, SA total of 135 laying quails (Coturnix coturnix japonica ), 9 weeks old, were divided into three dietary treatment groups. Three replicates were assigned to each treatment group consisting of 15 birds per cage. The diet was supplemented with 0, 100 and 200 ppm Yucca schidigera powder and given ad libitum to the quails for a period of 14 weeks. Body weight, egg production, feed consumption and feed efficiency were not different due to dietary treatments among the groups. Increased egg weight was determined in the control group. Yucca powder supplementation decreased serum glucose, cholesterol and triglyceride level in laying quails. Serum total protein concentration was not changed by dietary treatments but albumin level was decreased in quails fed 100 ppm yucca powder. Egg yolk cholesterol concentration was not significantly different among the groups but tended to decline (11.5%) as a result of yucca supplementation. Red Blood Cell (RBC) and White Blood Cell (WBC) counts, packed cell volume (PCV), mean corpuscular volume (MCV) and mean corpuscular haemoglobin (MCH) were not affected by supplementation of yucca powder. However, haemoglobin (HB) concentration was slightly increased and mean corpuscular haemoglobin concentration (MCHC) was significantly increased by 200 ppm yucca powder supplementation to the diet.Öğe Effects of ascorbic acid on cadmium-induced oxidative stress and performance of broilers(Humana Press Inc, 2005) Erdogan, Z; Erdogan, S; Celik, S; Unlu, AThe effects of cadmium on performance, antioxidant defense system, liver and kidney functions, and cadmium accumulation in selected tissues of broiler chickens were studied. Whether the possible adverse effects of cadmium would reverse with the antioxidant ascorbic acid was also investigated. Hence, 4 treatment groups (3 replicates of 10 chicks each) were designed in the study: control, ascorbic acid, cadmium, and cadmium plus ascorbic acid. Cadmium was given via the drinking water at a concentration of 25 mg/L for 6 wk. Ascorbic acid was added to the basal diet at 200 mg/kg either alone or with cadmium. Cadmium decreased the body weight (BW), body weight gain (BWG), and feed efficiency (FE) significantly at the end of the experiment, whereas its effect on feed consumption (FC) was not significant. Cadmium increased the plasma malondialdehyde (MDA) level as an indicator of lipid peroxidation and lowered the activity of blood superoxide dismutase (SOD). Liver function enzymes, aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactate dehydrogenase (LDH), and gamma glutamyl transferase (GGT) activities were not changed by cadmium. Cadmium ingestion did not alter serum creatinine levels. Although the serum cadmium level was not elevated, cadmium mainly accumulated in the kidneys, liver, pancreas, and muscle. Ascorbic acid supplementation resulted in a reduction of MDA level previously increased by cadmium and a restoration in SOD activity. However, ascorbic acid did not ameliorate the growth inhibitory effect of cadmium nor did it prevent accumulation of cadmium in analyzed tissues. These data indicate that oxidative stress induced by cadmium, plays a role in decreasing the performance of broilers and that dietary supplementation by ascorbic acid might be useful in reversing the lipid peroxidation induced by cadmium and partly alleviating the adverse effect of cadmium on performance of broilers.Öğe The effects of dietary lead exposure and ascorbic acid on performance, lipid peroxidation status and biochemical parameters of broilers(Tubitak Scientific & Technological Research Council Turkey, 2005) Erdogan, Z; Erdogan, S; Aksu, T; Baytok, ELead is one of the ubiquitous environmental pollutants that induce a broad range of physiological and biochemical dysfunctions in animals. This study evaluated the effects of dietary lead exposure and ascorbic acid on performance, serum biochemical parameters, plasma malonclialdehyde and lead accumulation in broiler chickens. For this purpose, lead acetate at 200 mg/kg and ascorbic acid at 100 mg/kg were added to the diet alone or in combination for 42 days. A total of 120 broiler chicks were divided into 4 treatment groups: control, ascorbic acid, lead, and lead + ascorbic acid. By the end of the study, lead caused body weight and body weight gain to decrease significantly, although its effects on feed consumption and the feed conversion ratio were not significant. While lead did not alter the serum lactate dehydrogenase, aspartate aminotransferase or alanine aminotransferase activities or albumin or total protein concentrations, it increased malondialdehyde (P < 0.001) and triglyceride (P < 0.01) levels. Although the lead contents of the serum and muscle were unchanged, lead was accumulated in the liver and kidneys (P < 0.001). Our results showed that lead (200 mg/kg diet) had an inhibitory effect on the growth of broilers and appeared to be inducing lipid peroxidation. The addition of ascorbic acid to the diet reduced the plasma malondialdehyde levels induced by lead and tended to reduce the inhibitory effect of lead on growth. It is concluded that the addition of higher doses of ascorbic acid to the diet may be more efficacious in fully reversing the negative effect of lead on growth.Öğe Efficacy of tribasic copper chloride (TBCC) to reduce the harmful effects of aflatoxin in broilers(Tubitak Scientific & Technological Research Council Turkey, 2005) Çelík, S; Erdogan, Z; Erdogan, S; Bal, RThis study was conducted to evaluate the effects of copper as tribasic copper chloride on serum biochemical values and growth performance of broilers intoxicated with aflatoxins. Aflatoxins significantly decreased the level of albumin (P < 0.001), total protein (P < 0.001) and total cholesterol (P < 0.01), and increased the activities of alanine amino transferase, L-lactic dehydrogenase and alkaline phosphatase (P <= 0.001) in serum. These AF-induced changes were significantly improved by adding tribasic copper chloride to the diet. The decrease in serum copper concentration induced by aflatoxin was reversed by tribasic copper chloride. Serum zinc concentrations were not affected in tribasic copper chloride and tribasic copper chloride plus aflatoxin groups. Serum iron levels decreased in all the treatment groups significantly (P < 0.05). Aflatoxins caused significant decrease in the body weight gain and significant increase in the feed conversion ratio. Adverse effects of aflatoxins on feed conversion ratio were reversed by tribasic copper chloride supplementation to the diet. It is suggested that tribasic copper chloride might be used for reducing the adverse effects of aflatoxins in broiler production.Öğe Isolation and characterization of verocytotoxin-producing Escherichia coli O157 from Turkish cattle(Elsevier, 2006) Aslantas, Ö; Erdogan, S; Cantekin, Z; Gülaçti, I; Evrendilek, GAThe objective of this study was to collect rectal swabs from the cattle in a slaughterhouse located in Hatay (Turkey) immediately after slaughter for the isolation and characterization of verotoxin-producing Escherichia coli O157 in each month during a 1-year period. The rectal swab samples were analyzed for the isolation of E. coli O157 through preenrichment, immunomagnetic separation and selective plating on CT-SMAC agar. E. coli O157 was isolated from 77 (13.6%) of the samples. The presence of E. coli O157 changed during a 1-year period, in that the occurrence of E. coli O157 was the highest in July and November and lowest in February. A total of 66 isolates out of 77 were seroytpe O157:H7 and 11 were serotype O157:NM. PCR analysis of E. coli O157 virulence genes revealed that all O157:H7/NM were positive for rbf(O157), 74 positive for EhlyA, 72 positive for eaeA, 62 positive for vtx2, and 3 positive for both vtx1 and vtx2. It was presented by cytotoxicity tests that many of E. coli O157 isolates showed high cytotoxicity on Vero cells. All of the isolates containing EhlyA showed enterohaemolysin production. (c) 2005 Elsevier B.V. All rights reserved.Öğe Seasonal and locational effects on serum, milk, liver and kidney chromium, manganese, copper, zinc, and iron concentrations of dairy cows(Humana Press Inc, 2004) Erdogan, S; Celik, S; Erdogan, ZChromium (Cr), manganese (Mn), copper (Cu), zinc (Zn), and iron (Fe) concentrations were quantified in serum (n = 112), milk (n =: 112), liver (n = 70), and kidney samples (n = 67) of dairy cows from an iron-steel processing region (Payas-Iskenderun) and from an area free of industrial pollution (Antakya) in Hatay, located in Southern Turkey. Samples were collected in the summer and winter and element determinations were carried out by inductively coupled plasma-atomic emission spectrometry. The mean concentrations of selected elements in serum were found to be similar in both regions. Milk samples collected from the nonindustrial region in the summer had higher Cr, Mn, and Zn concentrations than the polluted region. The liver Cu and kidney Mn levels of samples taken from the industrial region in winter were higher than samples of the unpolluted region. Copper and Fe concentrations in milk, Cr, Mn, Zn, and Fe levels in the liver, and Cr, Cu, Zn, and Fe levels in kidney samples were not found to be different among the regions in both seasons. Copper concentrations were below the critical level in the 25% of serum and 32% of liver samples analyzed in this study. Fifteen percent of serum samples and most of the liver samples had lower amounts of Zn than other reported studies. Although slight differences were observed between the industrial and nonindustrial regions, industrial activities and seasonal changes had no significant effect on selected element concentrations on cows and their milk.Öğe Some mineral substance levels in serum of sheep and goat grazing in Hatay region(Tubitak Scientific & Technological Research Council Turkey, 2002) Erdogan, S; Ergün, Y; Erdogan, Z; Kontas, TThis study was carried out on 93 sheep and 92 goats which were all clinically healthy and raised in the pasture conditions in the Hatay region. Blood samples were collected from the jugular vein between June and July (1999) in Altinozu, Reyhanli, Yayladagi, Samandagi and Dortyol province. Serum samples were analysed by atomic absorption spectrophotometry for copper and zinc. Sodium and potassium levels were determined by flame photometry, calcium levels were quantified by Eppendorf photometry, magnesium was measured by spectrophotometry and selenium was determined by fluorometry. In the Hatay region, Mg 1.08 +/- 0.02 mmol/L, Ca 2.38 +/- 0.06 mmol/L, Na 149.07 +/- 2.06 mmol/L, K 3.05 +/- 0.07 mmol/L, Cu 0.32 +/- 0.01 ppm, Zn 0.22 +/- 0.01 ppm and Se 0.12 +/- 0.01 ppm were found in sheep; Mg 1.13 +/- 0.02 mmoI/L, Ca 2.11 +/- 0.05 mmoIIL, Na 149.37 +/- 2.65 mmol/L, K 3.06 +/- 0.05 mmol/L, Cu 0.33 +/- 0.02 ppm, Zn 0.21 +/- 0.00 ppm and Se 0.16 +/- 0.00 ppm were measured in goats. Calcium, Mg, Na and Se levels were found to be within the normal range in both sheep and goats. However, K levels were slightly lower in some regions, and Cu and Zn levels were under critical levels in all regions. It is concluded that Cu and Zn should be added to the rations of goats and sheep.Öğe Subclinical fatty liver syndrome in Damascus goats(Indian Veterinary Journal, 2003) Gonenci, R; Durgut, R; Erdogan, S; Bal, R; Celik, S[Abstract Not Available]
