165 research outputs found
Melatonin in Cardiovascular Diseases
Melatonin is an endocrine product released from the gland known as the pineal gland and is predominantly secreted during the night. Light exerts an inhibitory effect on melatonin secretion in the pineal gland. The suprachiasmatic nucleus controls pineal melatonin synthesis and its release via the peripheral sympathetic nervous system, which includes synapses in the intermediolateral cell column of the thoracic cord and its projection toward the superior cervical ganglia. Melatonin regulates many physiological functions in the body through membrane receptors and nuclear binding sites. In a chick study, the presence of melatonin receptors in cardiomyocytes was reported and, in another study, MT1 and MT2 membrane receptors were identified in left ventricular cardiomyocytes of the human heart. For this reason, it is suggested that melatonin has some regulatory effects on the cardiovascular system. Ischemic heart disease and myocardial infarctions are the main cause of cardiovascular death. Studies have shown that melatonin applications reduce the amount of blood cholesterol, LDL, and triglyceride and increase the amount of HDL. In light of these data, it can be said that melatonin is an important cardiovascular system protector. In this chapter, the protective effects and mechanisms of melatonin on the cardiovascular system will be discussed
The Relationship of Some Neurodegenerative Diseases with Endoplasmic Reticulum Stress and Histopathological Changes in These Diseases: An Overview
The endoplasmic reticulum (ER) is an organelle responsible for protein production in the cell and provides hemostasis in the cell. ER stress is stimulated by folded proteins, while the unfolded protein response (UPR) creates a response to ER stress and provides the cell survival. UPR modulation in mammals is provided with three major ER stress sensors, including transmembrane kinase 1, protein kinase-like ER kinase, and activating transcription factor 6. Because neurons are susceptible to misfolded proteins, severe or prolonged ER stress activates apoptotic cell death signals in the cell. Neurodegenerative diseases characterized by this condition are Alzheimer’s disease, Parkinson’s disease, amyotrophic lateral sclerosis, and Huntington’s disease, characterized by the accumulation and aggregation of misfolded proteins. In addition, ER stress can lead to depression, schizophrenia, sleep disruption, and post-traumatic stress disorders. Neurons are highly susceptible to protein misfolding and apoptotic cell death. For this reason, UPR modulation contributes to preventing the neurodegenerative process in cells with misfolded protein folding. The relationship between ER stress, UPR, and neuropathology is significant for understanding this process. This section will discuss the effects of ER stress between UPR modulation and neurodegenerative disorders, and the histopathological changes in the mentioned neurodegenerative diseases will be mentioned
Oxidative Stress and Autophagy
Free radical production related with many stress factors including radiation, drugs, ageing and trauma plays a key role in cell death. Notwithstanding, free radicals can cause pathology in a variety of diseases through oxidative stress: Under oxidative stress, excessive production of free radicals can trigger cell death by primarily DNA and all cellular macromolecule damages. Also, excessive free radicals have a role in early inducers of autophagy cell death upon nutrient deprivation. Autophagy is physiologic process of eukaryotic systems, which have significant role in adaptation to oxidative stress by degradation of metalloproteins and oxidatively damaged macromolecules. By oxidizing, membrane injuries allow the leakage of enzymes and contribute to cell damage. However, recent publications demonstrate the protecting role of lysosome system during excessive reactive oxygen species (ROS) production by the elimination of damaged proteins or organelles. Activation of autophagic or lysosomal system can eliminate the oxidizing components of cell in oxidative stress response. This chapter aims to provide the novel insight data for oxidative damage-mediated autophagy as well as their metabolic networks
Synthesis and Types of Selenoproteins and Their Role in Regulating Inflammation and ER Stress Signaling Pathways: Overview
Selenium (Se) is one of the trace elements that play an important role in many biological processes in the living body. Selenium acts in the body mainly in its forms called selenoprotein. Selenoproteins play a role in various events such as oxidative stress, immunity, cancer, inflammation, and endoplasmic reticulum stress. In selenium deficiency, the expression of selenoproteins and thus their activity decrease. In this case, some reactions such as increased oxidative stress, weakened immunity, endoplasmic reticulum stress, and inflammation cannot be prevented. The main source of selenium is food, and a diet poor in selenium causes selenium and therefore selenoprotein deficiency. This chapter will present information about the synthesis of selenoproteins and their role, especially in inflammation and endoplasmic reticulum stress response
Improved Cryptanalysis of SHAMATA-BC
We state the design flaws of the 1-round block cipher SHA\-MATA-BC, designed by Fleishmann and Gorski by using the building blocks of SHAMATA hash function. We fix the flaws and then show that the amended version of SHAMATA-BC is much weaker. We believe that there is no connection between security level of SHAMATA as a hash function and that of SHAMATA-BC as a block cipher
Detection of prevalence, antibiotic resistance and virulence factors of enterococcus spp. ısolated from ready to eat foods
Bu çalışmada tüketime hazır bazı gıdalarda Enterokok türlerinin prevalansı, antibiyotik dirençliliği ve virülans faktörleri belirlendi. Analize alınan 187 gıda örneğinin 112 (%59,9)’sinde 114 Enterococcus spp. izole edildi. Et ürünlerinden 39 (%34,8), peynirlerden 42 (%37,5), salatalardan 25’i (%22,3) ve helva örneklerinden 8 (%7,1)’inde Enterococcus spp. izolatı elde edildi. Antibiyotik dirençlilik testi sonuçlarına göre, elde edilen Enterokok izolatlarının çalışmada kullanılan antibiyotiklerden en az dördüne dirençlilik gösterdiği tespit edildi. İzolatların hiçbirinde gelatinaz aktivitesi gözlenmezken, 36’sında (%31,6) hemolizin aktivitesi pozitif tespit edildi. Sonuç olarak starter kültür olarak kullanılabileceği ve insanlar için zararsız olduğu düşünülen bazı Enterokok türlerinin, virülens faktörler ve sahip olabilecekleri antimikrobiyal direnç bakımından halk sağlığı ve gıda güvenliği açısından bir risk oluşturabilmektedir. Bu nedenle gıda endüstrisinde starter olarak kullanılabilecek Enterokok türleri, patojenite özelliği bulunmayan ve antibiyotik direnç genlerine sahip olmayanlardan seçilmelidir.In this study, we identified the prevalence of Enterococcus spp., antibiotic resistance and several virulence factors of some ready-to-eat foods. Totally 114 Enterococcus spp. were isolated in 112 (59.90 %) of the 187 food samples analysed. Enterococcus spp. isolates were obtained from 39 samples of meat products (34.80 %), 42 samples of cheese brands (37.50 %), 25 samples of salads (22.30 %) and eight samples of halva (7.10 %). According to the results of the antibiotic resistance test, the Enterococci isolates obtained were determined to show resistance to at least 4 of the antibiotics used in the study. While no gelatinase activity was observed in any of the isolates, haemolysin activity was observed to be positive in 36 of them (31.60 %). As a result, having been regarded for years as harmless and reported likely to be used as a starter culture, some Enterococcus spp. pose a risk to public health and to food safety since they have virulence factors and strong antimicrobial resistance. For this reason, the Enterococcus spp. to be used as a starter in the food industry should be chosen from among those that don’t have pathogenicity and antibiotic resistance genes
Analysis of roof live loads in industrial buildings
In design, structural engineers must have a clear understanding of live loads, both qualitatively and statistically. For decades, multiple studies have been published that relate live loads for floor loads in various occupancies such as offices and residences. However, survey data or probabilistic live load models for industrial building roofs are difficult to find. There are recommendations in major standards used in the modern world that give design live load values for roofs based on the accessibility of the rooftops. On the other hand, engineers may not understand the origin of these values. Comparison is made between current U.S standards for roof live loads and standards used in other parts of the world. To ensure that the most accurate live load assessment is implemented in the design, our understanding of live loads should be updated on a regular basis. Furthermore, in the United States, the current roof live load design value is 0.96 kN/m2 (20 psf), which is much greater than the values recommended by European, Australian, and Chinese standards. As a result, determining the source of live load on industrial building roofs is essential. To cover the gap in the literature, this article gives survey methodology and probabilistic studies related to design live load value on roofs. The sensitivity of existing probabilistic models to mean, variance, and time duration was also investigated.This work is part of the research project Roof Live Load Models for Metal Buildings which is sponsored by the Metal Building Manufacturers Association (MBMA) and the Steel Deck Institute (SDI). The authors would like to thank Dr. Zhanjie Li, Associate Professor at Suny Polytechnic, for his help translating the Chinese standards
Doğu Akdeniz Bölgesi’nde Organik Turunçgil Üretiminde Hastalık, Zararlı ve Yabancı Otların Mücadelesinin Yönetimi
Bu çalışma, 2003-2006 yılları arasında Hatay (Dörtyol) ve Mersin (Erdemli) illerinde yürütülmüş olup, çalışmada Mars Seedless Altıntop ve Valensiya Portakal çeşidinde zararlı, hastalık ve yabancı otlara karşı organik tarıma uygun mücadele yöntemlerinin uygulanabilirliği araştırılmıştır. Çalışmada her iki turunçgil çeşidinin bulunduğu alanlarda Organik Tarım ve Entegre Mücadele uygulamaları birlikte yürütülmüştür. Organik tarım yapılan bahçelerde organik ürün sertifikası alımına yönelik gerekli denetlemeler yaptırılarak ürün sertifikalandırılmıştır.
Tüm bahçelerde bulunan zararlı ve doğal düşmanlar gözle inceleme ve darbe yöntemi ile saptanmıştır. Organik tarım bahçelerinde, ekonomik zarar eşiğini aşan zararlılara (Turunçgil Unlubiti, Turunçgil Kırmızı Örümceği, Yıldız Koşnili) karşı doğal düşman salımı, kükürt ve yazlık beyaz yağ uygulaması yapılarak mücadele edilmiştir. Hastalık etmenleri makroskopik ve mikroskobik incelemelerle belirlenmiştir. Denemenin yürütüldüğü Mars Seedless Altıntop bahçesinde Gövde Zamklanma Hastalığı [Phytopthora citropthora (Sm. et Sm) Leonian] tespit edilmiştir. Bu hastalıkla mücadele için enfekteli ağaçların gövdesinde kabuk temizliği yapılmış temizlenen yara yerlerine %2 oranında Bordo Bulamacı uygulanmıştır. Yabancı otlarla organik yetiştiricilikte mücadele amacıyla örtücü bitki uygulaması yapılmıştır. Dört örtücü bitki türü; arpa, İngiliz Çimi, Adi Fiğ, Acem Üçgülü denemeye alınmıştır. Toprağı kaplama alanı yönünden en yüksek değerler, ile yabancı ot kaplama alanı ve birim alandaki yabancı ot tür ve sayısı yönünden en düşük değerler arpa ve fiğden alınırken, yaş ve kuru ağırlık yönünden en yüksek değer yine fiğ parselinden elde edilmiştir. Bahçelerde Turunçgil Nematodu (Tylenchulus semipenetrans Cobb.) da belirlenmiş ancak populasyonları zarar eşiğinin altında bulunmuştur.
Parsellerde kullanılan çiftlik gübresi ve yeşil gübre toprak ve yaprak analizleri sonuçlarına göre uygulanmıştır. Kullanılan her türlü girdiler ve yapılan işlemler Tarım Bakanlığınca yayımlanan yönetmeliğe uygun olarak kontrol ve sertifikasyon kuruluşunun da onayı ile seçilmiştir. Her yıl meyve hasat döneminde kalıntı analizleri ve pomolojik analizler yaptırılmış, bir üretim periyodu sonunda ağaç başına ortalama verim belirlenmiştir. Proje çalışmaları, ürüne “organik ürün” sertifikası veren danışman firma tarafından kontrol edilmiş ve çalışmada organik meyve elde edilmiştir
Royal Jelly Modulates Oxidative Stress and Apoptosis in Liver and Kidneys of Rats Treated with Cisplatin
Cisplatin (CDDP) is one of the most active cytotoxic agents in the treatment of cancer and has adverse side effects such as nephrotoxicity and hepatotoxicity. The present study was designed to determine the effects of royal jelly (RJ) against oxidative stress caused by CDDP injury of the kidneys and liver, by measuring tissue biochemical and antioxidant parameters and investigating apoptosis immunohistochemically. Twenty-four Sprague Dawley rats were divided into four groups, group C: control group received 0.9% saline; group CDDP: injected i.p. with cisplatin (CDDP, 7 mg kg−1 body weight i.p., single dose); group RJ: treated for 15 consecutive days by gavage with RJ (300 mg/kg/day); group RJ + CDDP: treated by gavage with RJ 15 days following a single injection of CDDP. Malondialdehyde (MDA) and glutathione (GSH) levels, glutathione S-transferase (GST), glutathione peroxidase (GSH-Px), and superoxide dismutase (SOD) activities were determined in liver and kidney homogenates, and the liver and kidney were also histologically examined. RJ elicited a significant protective effect towards liver and kidney by decreasing the level of lipid peroxidation (MDA), elevating the level of GSH, and increasing the activities of GST, GSH-Px, and SOD. In the immunohistochemical examinations were observed significantly enhanced apoptotic cell numbers and degenerative changes by cisplatin, but these histological changes were lower in the liver and kidney tissues of RJ + CDDP group. Besides, treatment with RJ lead to an increase in antiapoptotic activity hepatocytes and tubular epithelium. In conclusion, RJ may be used in combination with cisplatin in chemotherapy to improve cisplatin-induced oxidative stress parameters and apoptotic activity
Volume CXIV, Number 4, November 7, 1996
Objective: Turner syndrome (TS) is a chromosomal disorder caused by complete or partial X chromosome monosomy that manifests various clinical features depending on the karyotype and on the genetic background of affected girls. This study aimed to systematically investigate the key clinical features of TS in relationship to karyotype in a large pediatric Turkish patient population.Methods: Our retrospective study included 842 karyotype-proven TS patients aged 0-18 years who were evaluated in 35 different centers in Turkey in the years 2013-2014.Results: The most common karyotype was 45,X (50.7%), followed by 45,X/46,XX (10.8%), 46,X,i(Xq) (10.1%) and 45,X/46,X,i(Xq) (9.5%). Mean age at diagnosis was 10.2±4.4 years. The most common presenting complaints were short stature and delayed puberty. Among patients diagnosed before age one year, the ratio of karyotype 45,X was significantly higher than that of other karyotype groups. Cardiac defects (bicuspid aortic valve, coarctation of the aorta and aortic stenosis) were the most common congenital anomalies, occurring in 25% of the TS cases. This was followed by urinary system anomalies (horseshoe kidney, double collector duct system and renal rotation) detected in 16.3%. Hashimoto's thyroiditis was found in 11.1% of patients, gastrointestinal abnormalities in 8.9%, ear nose and throat problems in 22.6%, dermatologic problems in 21.8% and osteoporosis in 15.3%. Learning difficulties and/or psychosocial problems were encountered in 39.1%. Insulin resistance and impaired fasting glucose were detected in 3.4% and 2.2%, respectively. Dyslipidemia prevalence was 11.4%.Conclusion: This comprehensive study systematically evaluated the largest group of karyotype-proven TS girls to date. The karyotype distribution, congenital anomaly and comorbidity profile closely parallel that from other countries and support the need for close medical surveillance of these complex patients throughout their lifespa
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