Browsing by Author "Ozkan, S."

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Clinical Subtypes, Seasonality, and Short-Term Prognosis of Guillain-Barre Syndrome in an Eastern City of Turkey
(Asean Neurological Assoc, 2022) Kiraz, M.; Yilgor, A.; Milanlioglu, A.; Cilingir, V; Cagac, A.; Ozkan, S.
Background & Objective: This study aimed to analyze the frequency Guillain-Barre syndrome (GBS) subtypes and their relationship with clinical characteristics, seasonal variations and early prognosis in Van City, Turkey. Methods: Patients with GBS who were admitted between January 2007 and December 2017 and diagnosed with acute inflammatory demyelinating neuropathy (AIDP), acute motor axonal neuropathy (AMAN) or acute motor sensory axonal neuropathy (AMSAN) were reviewed. Demographics, season of clinical onset, history and type of preceding infection, the Hughes Disability Score (HDS) at admission and discharge were recorded. Results: Of a total 100 patients, 51% was diagnosed with AIDP, 25% with AMAN and the remaining 24% with AMSAN subtype. The most common seasonal onset was during the spring (34%), followed by the fall (30%). The history of gastroenteritis (GE) was present in 26% of the patients and these patients were more likely to have AMAN and AMSAN subtypes. HDS on admission and at discharge were significantly higher in patients with AMAN and AMSAN compared to those with AIDP (p=0.003 and p<0.001, respectively). The most important predictor of poor outcome at discharge was HDS on admission explaining between 50% and 80% of the total variance.Conclusion: There is a high prevalence of AMAN and AMSAN subtypes in Eastern region of Turkey. The history of GE, which is also commonly found in patients with GBS in this region, is more likely detected in patients with AMAN and AMSAN subtypes. Finally, clinical severity on admission is the most important contributor to clinical outcome at discharge.
Dietary Vitamin E (α-Tocopherol Acetate) and Selenium Supplementation From Different Sources: Performance, Ascites-Related Variables and Antioxidant Status in Broilers Reared at Low and Optimum Temperatures
(Taylor & Francis Ltd, 2007) Ozkan, S.; Malayoglu, H. Basmacioglu; Yalcin, S.; Karadas, F.; Kocturk, S.; Cabuk, M.; Ergul, M.
1. This study compared the effect of dietary supplementation with organic or inorganic selenium (Se) sources plus control amounts or large amounts of vitamin E (alpha- tocopherol acetate) in broilers raised at control ( 20 to 24 degrees C) or low ( 14 center dot 5 to 16 center dot 8 degrees C) temperatures after 2 weeks of age. 2. The following dietary treatments were used from one day old. Diet 1, the control diet, comprised a commercial diet containing 0 center dot 15 mg/ kg inorganic Se and 50 mg vitamin E/kg feed. Diet 2 was the same as diet 1, supplemented with 0 center dot 15 mg/ kg inorganic Se. Diet 3 was the same as diet 2 but was supplemented with 200 mg/ kg vitamin E. Diet 4 was the same as diet 1, but inorganic Se was replaced with 0 center dot 30 mg/ kg organic Se. Diet 5 was the same as diet 4, supplemented with 200 mg/ kg vitamin E. 3. Low temperature reduced the growth rate of broilers; however, at 6 weeks, there were no differences in the body weights of birds fed on organic Se supplemented diets housed at low or control temperature. The feed conversion ratio was significantly affected by low temperature but not by diet. The heterophil/ lymphocyte ratio was higher in chicks after one week in the cold, indicating mild stress. Blood triiodothyronine levels were significantly higher in birds after 1 and 4 weeks in the cold but thyroxin was not affected. 4. Organic Se supplementation increased relative lung weight at the control temperature, which might lead to greater respiratory capacity. Relative spleen weight significantly decreased in broilers fed diets supplemented with inorganic Se under cold conditions, a possible indication of chronic oxidative stress. 5. At the low temperature, supplementation with organic Se alone, or with inorganic Se and vitamin E increased glutathione peroxidase ( GSHPx) activity and glutathione ( GSH) concentration in the liver of broilers, which may indicate increased activity of birds' antioxidant defence against suboptimal environments.
The Effects of Feed Restriction and Ambient Temperature on Growth and Ascites Mortality of Broilers Reared at High Altitude
(Oxford Univ Press, 2010) Ozkan, S.; Takma, C.; Yahav, S.; Sogut, B.; Turkmut, L.; Erturun, H.; Cahaner, A.
The development of ascites was investigated in broilers at low versus high altitudes, cold versus normal ambient temperatures (AT), and 3 feeding regimens. One-day-old chicks obtained at sea level were reared at high altitude (highA; 1,720 m; n = 576) with 2 AT treatments, low AT from 3 wk onward at highA (highA/cold) and normal AT from 3 wk onward at highA (highA/norm), or at sea level (normal AT from 3 wk onward at low altitude, lowA/norm; n = 540). Under highA/cold, AT ranged between 16 to 17 degrees C in the fourth week, 17 to 19 degrees C in the fifth week, and 19 to 21 degrees C thereafter. Under highA/norm and lowA/norm, AT was 24 degrees C in the fourth week and ranged between 22 to 24 degrees C thereafter. Broilers in each condition were divided into 3 groups: feed restriction (FR) from 7 to 14 d, FR from 7 to 21 d, and ad libitum (AL). Ascites mortality and related parameters were recorded. Low mortality (0.4%) occurred under lowA/norm conditions. Under highA/norm, mortality was lower in females (8.6%) than in males (13.8%) and was not affected by the feeding regimen. The highA/cold treatmentresulted in higher mortality but only in males; it was 44.2% among highA/cold AL-fed males and only about 26% under the FR regimens, suggesting that FR helped some males to better acclimatize to the highA/cold environment and avoid ascites. However, mortality was only 13.3% in AL-fed males at highA/norm and FR did not further reduce the incidence of ascites under these conditions. Thus, avoiding low AT in the poultry house by slight heating was more effective than FR in reducing ascites mortality at highA. Compared with FR from 7 to 14 d, FR from 7 to 21 d did not further reduce mortality and reduced growth. At 47 d, the majority of surviving broilers at highA had high levels of hematocrit and right ventricle: total ventricle weight ratio (>0.29), but they were healthy and reached approximately the same BW as their counterparts at low altitude. This finding may suggest that in broilers reared at highA from day of hatch, the elevation in hematocrit and in right ventricle: total ventricle weight ratio happens gradually and therefore is not necessarily indicative of ascites development.
Photoperiodic Lighting (16 Hours of Light:8 Hours of Dark) Programs During Incubation: 1. Effects on Growth and Circadian Physiological Traits of Embryos and Early Stress Response of Broiler Chickens
(Oxford Univ Press, 2012) Ozkan, S.; Yalcin, S.; Babacanoglu, E.; Kozanoglu, H.; Karadas, F.; Uysal, S.
This study was conducted to evaluate the effect of a 16L:8D photoperiod during incubation, either during the whole incubation period (Inc(0-21d)) or the last week of incubation (Inc(14-21d))1 on embryo growth, incubation performance, and light:dark rhythm of plasma melatonin and corticosterone in relation to early stress responses of newly hatched chicks to the posthatching environment. A dark incubation condition (Inc(Dark)) served as control. Three batches of eggs (n = 1,080, 1,320, 720) from Ross 308 broiler breeders were used in the experiment. Embryos from Inc(0-21d) presented a daily rhythm of melatonin at internal pipping and hatching, but Inc(Dark) embryos did not. The Inc(14-21d) group had rhythmic plasma melatonin at hatching only. A L:D rhythm of corticosterone was apparent at hatching. A significant incubation x sampling time interaction suggested that a lower increment in blood corticosterone level in Inc(0-21d) at 8 h posthatching (light period), as compared with hatching (dark period) values, might be associated with probable changes in the hypothalamic-pituitary-adrenal axis in Inc(0-21d) through incubation lighting. This finding may also suggest improved adaptation to the posthatching environment. Incubation lighting did not consistently affect brain malondialdehyde concentration; the only difference between groups was higher concentrations at hatching in Inc(14-21d), whereas incubation groups at the internal pipping stage had similar values. Mean relative asymmetry (RA) did not differ with incubation lighting. The malondialdehyde and RA results indicate that neither lighting nor darkness during the overall incubation exacerbated embryo oxidative and developmental stress. An increased breast muscle weight was observed at hatching only in Inc(14-21d). The Inc(0-21d) group had increased embryo weights relative to egg weight and decreased residual yolk but had no effect on chick weight, relative heart and liver (% of embryo weight), hatch-ability, embryo mortality, incubation time, oxidative stress, or mean RA. In conclusion, these results provide further evidence that photoperiodic lighting during incubation (Inc(0-21d)) may improve adaptation of chicks to a novel environment at hatching, possibly giving birds a better start for early posthatching development.
Photoperiodic Lighting (16 Hours of Light:8 Hours of Dark) Programs During Incubation: 2. Effects on Early Posthatching Growth, Blood Physiology, and Production Performance in Broiler Chickens in Relation To Posthatching Lighting Programs
(Oxford Univ Press, 2012) Ozkan, S.; Yalcin, S.; Babacanoglu, E.; Uysal, S.; Karadas, F.; Kozanoglu, H.
Photoperiodic incubation lighting might improve bird adaptation to a novel environment at hatching for a better start in early posthatching development. We evaluated the effect of 16L:8D lighting for either the whole incubation period (Inc(0-21d)) or the last week of incubation (Inc(14-21d) on early posthatching growth, blood melatonin, and corticosterone at 6 d as well as malondialdehyde levels in brain tissue, relative asymmetry, and overall broiler performance as an interaction with the posthatching lighting programs. Dark incubation conditions (Inc(Dark)) served as control. There were 3 incubation batches in the experiment. Chicks from 2 of 3 batches were reared either at 16L:8D or under continuous lighting (24 h) through 6 d posthatching. Batch 3 chicks were reared to 35 d under either 16L:8D or 23L:1D. The main finding was a significant incubation x posthatching lighting interaction for 35-d BW in broilers. Although groups had similar BW under continuous lighting, Inc(0-21d) and Inc(14-21d) broilers were respectively 94 and 78 g heavier than Inc(Dark) birds under 16L:8D at 35 d. Lighted incubation groups increased 0 to 6 d of gain and had higher d-6 breast muscle weights with no effect on other traits measured. Posthatching 16L:8D reduced the gain and d-6 breast muscle. Significant incubation x posthatching lighting and posthatching lighting x sampling time interactions for blood melatonin may indicate that Inc(0-21d) affects melatonin diurnal rhythms even at 6 d under continuous light. Lower blood corticosterone levels on d 6 in Inc(0-21d) chicks reared under 16L:8D posthatching may support our hypothesis that incubation lighting can modify the bird stress response, probably affecting the hypothalamic-pituitary-adrenal axis during ontogeny, and may improve adaptation to a similar environment posthatching. The lower malondialdehyde concentration in brain tissue of Inc(0-21d) birds on d 6 may indicate lower lipid peroxidation and thus lower oxidative stress compared with Inc(Dark). These results provide further evidence that Inc(0-21d) may improve both bird adaptation to a similar photoperiodic environment and growth, probably through early entrainment of circadian physiology.