Deciphering a transcriptional regulatory code: modeling short-range repression in the Drosophila embryo

A well-defined set of transcriptional regulatory modules was created and analyzed in the Drosophila embryo.Fractional occupancy-based models were developed to explain the interaction of short range transcriptional repressors with endogenous activators by using quantitative data from these modules.Our fractional occupancy-based modeling uncovered specific quantitative features of short-range repressors; a complex nonlinear quenching relationship, similar quenching efficiencies for different activators, and modest levels of cooperativityThe extension of the study to endogenous enhancers highlighted several features of enhancer architecture design in Drosophila embryos

Štetni učinci pušenja tijekom trudnoće na DNA i razine reaktivnih oblika kisika (ROS) u krvi majke i novorođenčeta

Some of the genotoxic/carcinogenic substances or metabolites in cigarette smoke are capable of passing through the placenta and harming a newborn’s health. Smoking is also known as a factor in the formation of oxidative damage and the main mechanism involved in the carcinogenic process. Predetermining this genotoxic risk can be successfully achieved by measuring certain parameters of oxidative stress. The comet assay is considered an important biomarker for the evaluation of genotoxic substances and is effective for detecting DNA damage caused by smoking. This study examined third trimester bloods and the cord blood of 28 actively smoking and 22 non-smoking mothers in terms of DNA damage and oxidative stress parameters. Cu/Zn superoxide dismutase (CuZn-SOD), malondialdehyde (MDA), catalase (CAT), plasma nitrite/nitrates (NO2•/NO3•), selenium-dependent glutathione peroxidase (Se-GPx), Cu, and Zn levels were measured as indicators of oxidative damage. There were no significant increases in DNA damage of the actively smoking pregnant group in comparison with the non-smoking pregnant group, either in the third trimester or cord blood. Oxidative stress parameters of smoker and non-smoker groups were statistically different for MDA (p<0.05), CuZn-SOD (p<0.01), Se-GPx (p<0.05) values while the difference was not significant for NO2•/NO3•, CAT, Zn, and Cu values. The same values were also investigated in cord blood, and only NO2•/NO3• (p<0.01), Se-GPx (p<0.01 and CAT (p<0.001) values were found statistically different. Smoking mothers may have been exposed to more oxidative stress than non-smoking mothers.Pojedine genotoksične/kancerogene supstancije ili metaboliti u cigaretnom dimu mogu proći kroz posteljicu i naštetiti zdravlju novorođenčeta. Pušenje je također poznato kao čimbenik pri nastanku oksidacijskog oštećenja DNA i u procesu kancerogeneze. Ovaj genotoksični rizik može se uspješno odrediti mjerenjem određenih parametara oksidacijskog stresa. Komet-test smatra se važnim biološkim biljegom pri evaluaciji genotoksičnih supstancija i iznimno učinkovitim sredstvom pronalaženja oštećenja DNA uzrokovanih pušenjem. Ova studija proučava krv trudnica u trećem tromjesečju trudnoće i fetalnu krv 28 majki aktivnih pušačica te 22-ju majki nepušačica vezano za oksidacijska oštećenja DNA i parametre oksidacijskog stresa. Razine Cu/Zn superoksidne dismutaze (CuZn-SOD), malondialdehida (MDA), katalaze (CAT), nitrita/nitrata u plazmi (NO2-/NO3-), selenijeve glutation peroksidaze (Se-GPx), Cu i Zn mjerene su kao pokazatelji oksidacijskog oštećenja. Nije bilo značajnih povećanja oštećenja DNA u skupini trudnica aktivnih pušačica u usporedbi sa skupinom trudnica nepušačica, ni u krvi iz trećeg tromjesečja ni u fetalnoj krvi. Parametri oksidacijskog stresa pušačke i nepušačke skupine bili su statistički različiti za vrijednosti MDA (p<0,05), CuZn-SOD (p<0,01), Se-GPx (P<0,05), dok razlika nije bila značajna za vrijednosti NO2-/NO3-, CAT, Zn i Cu. Iste su vrijednosti ispitane i u fetalnoj krvi, a jedino su vrijednosti NO2-/NO3- (p<0,01), Se-GPx (p<0,01) i CAT (p<0,001) bile statistički različite. Vjerojatno je da su majke pušačice bile izložene većem oksidacijskom stresu od majki nepušačica

Oxidative stress and antioxidant defense in patients with chronic hepatitis C patients before and after pegylated interferon alfa-2b plus ribavirin therapy

BACKGROUND: Oxidative stress could play a role in pathogenesis of hepatitis C virus (HCV) infection. The aim of our study is to determine oxidant/antioxidant status of patients with chronic hepatitis C (CHC), and the effect of pegylated interferon alfa-2b plus ribavirin combination therapy on oxidative stress. METHODS: Nineteen patients with chronic HCV infection and 28 healthy controls were included in the study. In control and patient groups, serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels, erythrocyte malondialdehyde (MDA) levels, erythrocyte CuZn-superoxide dismutase (SOD), erythrocyte glutathione peroxidase (GSH-Px) activities were measured. After pegylated interferon alfa-2b and ribavirin combination therapy for 48 weeks, these parameters were measured again in the patient group. RESULTS: Serum MDA levels increased significantly in CHC patients (n:19), before the treatment when compared with healthy subjects (n:28) 9.28 ± 1.61, 4.20 ± 1.47 nmol/ml, p < 0.001 respectively. MDA concentration decreased significantly (p < 0.001) after the treatment as well as ALT, AST activity, in erythrocytes of these patients. Average antioxidant enzymes (superoxide dismutase and glutathione peroxidase) were significantly lower in erythrocytes of patients with CHC before treatment compared with the control group (both, p < 0.001). Chronic Hepatitis C patients after pegylated interferon alfa-2b and ribavirin therapy showed values of SOD, GSH-Px were significantly higher than pretreatment levels (both, p < 0.001). CONCLUSION: Our results show that patients with chronic HCV infection are under the influence of oxidative stress associated with lower levels of antioxidant enzymes. These impairments return to level of healthy controls after pegylated interferon alfa-2b plus ribavirin combination therapy of CHC patients. Although interferon and ribavirin are not antioxidants, their antiviral capacity might reduce viral load, and inflammation, and perhaps through this mechanism might reduce virus-induced oxidative stress

Utjecaj desflurana i sevoflurana na razine oksidativnog stresa u tkivima štakora

General anaesthetics are often used in patients who are under oxidative stress due to a critical illness or surgical trauma. Some anaesthetics may worsen oxidative stress and some may act as antioxidants. The aim of this study was to evaluate liver, brain, kidney, and lung tissue oxidative stress in rats exposed to desflurane and sevoflurane and in unexposed rats. The animals were divided in three groups: control (received only air); sevoflurane (8 %), and desflurane (4 %). After four hours of exposure, we evaluated the levels of malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), Cu, and Zn. Exposure to either of the anaesthetics significantly increased lung MDA levels compared to control (Mann-Whitney U test; P<0.05), probably because it is the tissue directly exposed to anaesthetic gases. Oxidative stress and antioxidant activity in other tissues varied between the desflurane and sevoflurane groups. Our results suggest that anaesthesiologist should not only be aware of the oxidative or antioxidative potential of anaesthetics they use, but should also base their choices on organs which are the most affected by their oxidative actionkisikovih radikala tako i zbog smanjene aktivnosti obrambenih sustava koji se mogu oduprijeti njihovu djelovanju. Stoga su saznanja o antioksidativnom kapacitetu anestetika koji se primjenjuju prije nekoga kirurškog zahvata vrlo važna i od velikog su kliničkog značenja. Sevofl uran i desfl uran su inhalacijski anestetici koji se učestalo rabe u svrhu uvođenja bolesnika u anesteziju. Cilj ovog istraživanja bio je utvrditi razine oksidativnog stresa u različitim tkivima štakora i usporediti razlike u odgovoru tkiva na izlaganje navedenim anesteticima. U tu svrhu razine oksidativnog stresa izmjerili smo u jetri, mozgu, bubrezima i plućima štakora podijeljenih u tri eksperimentalne skupine. Kontrolna skupina udisala je samo zrak, dok su druge dvije skupine izložene 8 %-tnomu sevofl uranu te 4 %-tnomu desfl uranu tijekom 4 h. Nakon završetka obrade životinje su žrtvovane i uzimani su im uzorci tkiva za biokemijske analize. Mjerena je razina malondialdehida (MDA), aktivnst enzima superoksid dismutaze (SOD) i glutation peroksidaze (GSH-Px) te razine bakra i cinka. Izloženost anesteticima izazvala je oksidativni stres u plućima, na što upućuje značajno povišena razina MDA (Mann-Whitney U-test P<0.05) izmjerena u plućnom tkivu štakora obiju izloženih skupina u odnosu na kontrolu. Plućno je tkivo u odnosu na ostala tkiva podložnije štetnim utjecajima reaktivnih kisikovih radikala vjerojatno stoga što je ono prvo izloženo plinovitim anesteticima nakon njihova ulaska u organizam. Razine oksidativnog stresa i antioksidativne aktivnosti koje smo izmjerili u ostalim tkivima bile su različite te su ovisile o primijenjenom anestetiku. Na osnovi dobivenih rezultata možemo zaključiti da bi se zbog različitog odgovora tkiva izbor anestetika trebao provoditi na individualnoj osnovi

Bursa'da kesilen ineklerin karaciğer kurşun düzeyleri

Bursa is a city of over two million with enormous environmental pollution problems. Lead, has an important role in environmental pollution, reaches to man with animal originated foods in ecosystems. In the presented research, cattle liver samples were obtained from the animals which had highway feeding. Five liver samples from Çalı, fıve from Akçalar and ten samples from Bursa Meat and Fish Foundation (EBK) slaughterhouses were provided All of the samples were ashed by nitric acid perchloric acid (4:2 v/v) and lead levels were measured by Atomic Absorption Spectrophotometer with graphite furnace. The estimated liver lead levels in Çalı, Akçalar and E.B.K samples were 0.397 mg/kg, 0.270 mg/kg and 0.248 mg/kg, respectively. Comparing to these values with other published data, it was observed that all samples had high lead levels. As conclusion, Bursa and surrounding are getting more polluted. These results were prompted us to carry out further investigation.İki milyonun üzerine varan nüfusuyla Bursa ciddi çevre kirliliği problemi ile karşı karşıya olan bir şehirdir. Bu kirlilikle önemli rolü olan kurşunun, ekasistemde insana ulaştığı en son nokta hayvansal kökenli gıdalardır. Sunulan çalışmada, anamnez ile şarampol besiciliği yaptığı belirlenen işletmeler ait ineklerden Çalı 'da 5, Akçalar da 5 ve E. B. K. 'da 10'ar adet karaciğer numunesi alındı. Nitrik asit perklorik asit (4:2 vlv) karışımı ile yaş olarak yakılıp, grafit fırınlı Atomik Absorpsiyon Spektrofotometresi yardımıyla kurşun (Pb) miktarları ölçüldü. Çalı'daki numunelerde 0.396 mg/kg., Akçalar' da 0.270 mg/kg ve E.B.K. 'da ise 0.248 mg/kg kurşun düzeyleri saptandı. Çalışma sonucu elde edilen bulgular, literatür verilerinden yüksek bulundu. Bu sonuçlar bizleri daha ayrıntılı çalışmalara yöneltildi

Determination of lead (Pb) contents of milk consumed in Bursa region

Yüzyıllardan beri çeşitli amaçlar için yaygınca kullanılan kurşun (Pb), insan ve hayvanlarda toksik yatması nedeniyle biyolojik öneme sahiptir. Sunulan çalışmada trafikten uzak, yoğun trafik akışına sahip yol kenarlarında ve sanayi bölgelerinde bulunan 25 adet çiftlikte beslenen ineklerden alınan süt örnekleri incelendi. Numunelerde kurşun düzeyi Atomik Absorbsiyon Spektrofotometresi kullanılarak ölçüldü. Pb düzeyi kontrol grubu diye nitelendirilen trafikten uzak bölgedeki 5 numunede 0.0231 ppm iken, yoğun trafiğe sahip yol kenarlarındaki bölgede 10 numunede 0.0342 ppm ve sanayi bölgesindeki 10 numunede ise 0.0907 ppm olarak saptandı. Elde edilen sonuçlar, Bursa yöresinde gerek trafik yoğunluğu ve gerekse sanayi bölgelerinin tüketilen sütlerdeki Pb miktarını etkilemekte olduğu ve çevre kirliliği açısından olumsuz sinyaller verdiğini vurgulamaktadır.Lead which has been used for centuries for different purposes had biological importance due to its toxicity for man and animals. In the presented study, milk samples obtained from 25 different farm located at; far from heavy traffic, in heavy traffic and in factory areas were investigated for lead (Pb) contents by Atomic Absorption Spectrophotometer. The average amount of Pb in the first group from 5 samples were 0.0231 ppm, in second group from 10 samples were 0.0342 ppm and in the third group from 10 samples were estimated as 0.0907 ppm. From this obtained data, it was emphasized that heavy traffic and industrial areas affected significantly the amount of Pb in milk and give negative signals for environmental pollution

Lipid peroxidation and antioxidant system in the blood of patients with Hodgkin's disease

Objectives: The purpose of this study was to measure the extent of lipid peroxidation and the status of antioxidants in patients with Hodgkin's disease