Transient changes in inflammatory and oxidative stress markers with total sleep deprivation

Sleep and Biological Rhythms - Sleep deprivation (SD) is known to modulate inflammatory and oxidative stress markers. How these markers change over the SD period have seldom been studied in healthy...     

Autophagy and mTOR pathways in mouse embryonic stem cell,lung cancer and somatic fibroblast cell lines

Embryonic developmental stages and regulations have always been one of the most intriguing aspects of science. Since the cancer stem cell discovery, striking for cancer development and recurrence, embryonic stem cells and control mechanisms, as well as cancer cells and cancer stem cell control mechanisms become important research materials. It is necessary to reveal the similarities and differences between somatic and cancer cells which are formed of embryonic stem cells divisions and determinations. For this purpose, mouse embryonic stem cells (mESCs), mouse skin fibroblast cells (MSFs) and mouse lung squamous cancer cells (SqLCCs) were grown in vitro and the differences between these three cell lines signalling regulations of mechanistic target of rapamycin (mTOR) and autophagic pathways were demonstrated by immunofluorescence and real-time polymerase chain reaction. Expressional differences were clearly shown between embryonic, cancer and somatic cells that mESCs displayed higher expressional level of Atg10, Hdac1 and Cln3 which are related with autophagic regulation and Hsp4, Prkca, Rhoa and ribosomal S6 genes related with mTOR activity. LC3 and mTOR protein levels were lower in mESCs than MSFs. Thus, the mechanisms of embryonic stem cell regulation results in the formation of somatic tissues whereas that these cells may be the causative agents of cancer in any deterioration.     

Amelioration of methotrexate-induced enteritis by melatonin in rats

The anti-tumour drug methotrexate (MTX) induces intestinal mucosa injury resulting in malabsorption and diarrhoea. The purpose of this study was to investigate whether exogenous melatonin could protect the gut from MTX-induced damage in rats. A single dose of MTX (20 mg kg(-1), i.p.) was followed by i.p. saline or melatonin injections (10 mg kg(-1), MTX + Mel) for the next 5 days. On the fifth day, intestinal transit was assessed using charcoal propagation. Rats were decapitated and small intestinal segments were fixed for light (LM) and scanning electron microscope (SEM) examinations. Other intestinal segments were stored to measure glutathione (GSH) and malondialdehyde (MDA) levels, myeloperoxidase (MPO) and ATPase activity. MTX led to loss of more than 10% of the initial body weight (p < 0.01). Conversely, weight loss was markedly less in the melatonin-treated MTX group (p < 0.05). Bowel motility was increased in MTX-treated rats, while the transit index in the MTX-Mel group was not different from the control group. MTX caused decreases in GSH levels and ATPase activity, with increases in MDA levels and MPO activity. These changes were reversed in MTX-Mel-treated rats (p < 0.05-p < 0.001). LM and SEM in the MTX group revealed desquamation of surface epithelium and glandular degeneration, while the epithelium was slightly damaged in the MTX-Mel group. In conclusion, the present study demonstrates that melatonin is capable of reversing MTX-induced intestinal dysfunctions, indicating that it may be beneficial in ameliorating the symptoms of chemotherapy-induced enteritis.     

Melatonin and N-acetylcysteine have beneficial effects during hepatic ischemia and reperfusion

This study was designed to study the effects of Melatonin (Mel) and N-Acetylcystein (NAC) on hepatic ischemia/reperfusion (I/R) injury in rats. For this purpose Wistar albino rats were subjected to 45 minutes of hepatic ischemia followed by 60 minutes of reperfusion period. Melatonin (10 mg/kg) or NAC (150 mg/kg) were administered alone or in combination, intraperitoneally, 15 minutes prior to ischemia and just before reperfusion. Serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels were determined to assess liver functions. Liver tissues were taken for determination of malondialdehyde (MDA) levels, an end product of lipid peroxidation; glutathione (GSH) levels, a key antioxidant; protein carbonyl concentration (protein oxidation) (PO), a specific marker of oxidative damage of proteins; and myeloperoxidase (MPO) activity, as an indirect index of neutrophil infiltration. Plasma ALT and AST activities were higher in ischemia/reperfusion group than in control. They were decreased in the groups given Mel, NAC or the combination. Hepatic GSH levels, significantly depressed by I/R, were elevated to control levels in the combination group, whereas treatment with Mel or NAC alone provided only a limited protection. Hepatic MDA and PO levels, and MPO activity were significantly increased by I/R. The increase in these parameters were partially decreased by Mel or NAC alone, whereas treatment with the combination reduced these values back to control levels. In conclusion, considering the dosages used, Mel appeared to be significantly more potent than NAC in reversing the oxidative damage induced by I/R. Our findings show that Mel and NAC have beneficial effects against the I/R injury and due to their synergistic effects, when administered in combination, may have a more pronounced protective effects on the liver.     

Receptor-mediated adenylyl cyclase activation through XLalpha(s), the extra-large variant of the stimulatory G protein alpha-subunit

XLalpha(s), the large variant of the stimulatory G protein alpha subunit (Gsalpha), is derived from GNAS1 through the use of an alternative first exon and promoter. Gs(alpha) and XLalpha(s) have distinct amino-terminal domains, but are identical over the carboxyl-terminal portion encoded by exons 2-13. XLalpha(s) can mimic some functions of Gs(alpha), including betagamma interaction and adenylyl cyclase stimulation. However, previous attempts to demonstrate coupling of XLalpha(s) to typically Gs-coupled receptors have not been successful. We now report the generation of murine cell lines that carry homozygous disruption of Gnas exon 2, and are therefore null for endogenous XLalpha(s) and Gs(alpha) (Gnas(E2-/E2-)). Gnas(E2-/E2-) cells transfected with plasmids encoding XLalpha(s) and different heptahelical receptors, including the beta2-adrenergic receptor and receptors for PTH, TSH, and CRF, showed agonist-mediated cAMP accumulation that was indistinguishable from that observed with cells transiently coexpressing Gs(alpha) and these receptors. Our findings thus indicate that XLalpha(s) is capable of functionally coupling to receptors that normally act via Gs(alpha).     

Stress‐induced multiple organ damage in rats is ameliorated by the antioxidant and anxiolytic effects of regular exercise

Our aim was to investigate the effects of moderate load, regular swimming exercise on stress‐induced anxiety, and associated oxidative organ injury. Male Sprague‐Dawley rats (n = 48) were either kept sedentary or submitted to swimming exercise for 8 weeks. Rats were then divided as non‐stressed, acute stress, and chronic stress groups. After acute or chronic stress (electric foot shocks) applications, rats were placed on a holeboard and the exploratory behavior was recorded to assess the anxiety. Rats were decapitated after the stress application. Acute and chronic stress induction led to increased serum cortisol levels as compared to non‐stressed groups. Plasma aspartate aminotransferase levels that were elevated in sedentary rats with both stress exposures were lower in trained rats. Malondialdehyde levels and myeloperoxidase activity were increased in the cardiac muscle, liver, stomach, and brain of the stressed rats with a concomitant reduction in the glutathione levels, while stress‐induced changes in malondialdehyde, myeloperoxidase, and glutathione levels were reversed in the trained animals. Exercise, which led to increased malondialdehyde and reduced glutathione levels in the skeletal muscle of the non‐stressed rats, also protected against stress‐induced oxidative damage. Regular exercise with its anxiolytic and antioxidant effects ameliorates stress‐induced oxidative organ damage by a neutrophil‐dependent mechanism. Copyright © 2010 John Wiley & Sons, Ltd.     

Migraine, Helicobacter pylori, and oxidative stress

BACKGROUND: The aim of this study was to ascertain whether oxidative stress is a causative factor of migraine attacks for Helicobacter pylori-infected migraineurs. MATERIALS AND METHODS: A total of 35 consecutive migraine patients without aura who came to gastroenterology polyclinic with various complaints and diagnosed H. pylori infection were included in the study group and compared with a group of 29 patients (control group) without migraine and H. infection. H. pylori infection was diagnosed by histopathological biopsies, which were taken by endoscopy (Olympus-GIFXQ240 endoscope). Both the diagnosis and the classification of migraine were made according to the International Headache Society criteria. Blood samples for nitric oxide were taken from patients with migraine during headache-free period as well as the control group. The interaction of nitric oxide was measured by the determination of both nitrite and nitrate concentrations in the sample. RESULTS: The study group included 31 women and 4 men (mean age 49 +/- 8 years) and the control group included 25 women and 4 men (mean age 52.6 +/- 11 years). The mean frequency of migraine attacks was 2.94 +/- 1.58 days/month and the mean duration of attacks was 21.2 +/- 3 hours. It was found that the study group has lower nitrate levels than the control group. CONCLUSIONS: Our results do not support the role of oxidative stress in patients suffering from H. pylori infection and migraine.     

A selective molecularly imprinted polymer for immobilization of acetylcholinesterase (AChE): an active enzyme targeted and efficient method

In the present study, we immobilized acetylcholinesterase (AChE) enzyme onto acetylcholine removed imprinted polymer and acetylcholine containing polymer. First, the polymers were produced with acetylcholine, substrate of AChE, by dispersion polymerization. Then, the enzyme was immobilized onto the polymers by using two different methods: In the first method (method A), acetylcholine was removed from the polymer, and then AChE was immobilized onto this polymer (acetylcholine removed imprinted polymer). In the second method (method B), AChE was immobilized onto acetylcholine containing polymer by affinity. In method A, enzyme‐specific species (binding sites) occurred by removing acetylcholine from the polymer. The immobilized AChE reached 240% relative specific activity comparison with free AChE because the active enzyme molecules bounded onto the polymer. Transmission electron microscopy results were taken before and after immobilization of AChE for the assessment of morphological structure of polymer. Also, the experiments, which include optimum temperature (25–65°C), optimum pH (3–10), thermal stability (4–70°C), kinetic parameters, operational stability and reusability, were performed to determine the characteristic of the immobilized AChE. Copyright © 2015 John Wiley & Sons, Ltd.     

Kinases and glutathione transferases: selective and sensitive targeting

Kinases, representing almost 500 proteins in the human genome, are responsible for catalyzing the phosphorylation reaction of amino acid residues at their targets. As the largest family of kinases, the protein tyrosine kinases (PTKs) have roles in controlling the essential cellular activities, and their deregulation is generally related to pathologic conditions. The recent efforts on identifying their signal transducer or mediator role in cellular signaling revealed the interaction of PTKs with numerous enzymes of different classes, such as Ser/Thr kinases (STKs), glutathione transferases (GSTs), and receptor tyrosine kinases (RTKs). In either regulation or enhancing the signaling, PTKs are determined in close interaction with these enzymes, under specific cellular conditions, such as oxidative stress and inflammation. In this concept, intensive research on thiol metabolizing enzymes recently showed their involvement in the physiologic functions in cellular signaling besides their well known traditional role in antioxidant defense. The shared signaling components between PTK and GST family enzymes will be discussed in depth in this research review to evaluate the results of recent studies important in drug targeting for therapeutic intervention, such as cell viability, migration, differentiation and proliferation.     

A prospective epidemiologic survey on the prevalence of onychomycosis and dermatophytosis in male boarding school residents

Dermatophyte infections and onychomycosis are not usually serious in term of mortality; however, they may have significant clinical consequences such as secondary bacterial infections, chronicity, therapeutic difficulties and esthetic disfigurement in addition to serving as a reservoir of infection. Our aim was to determine the prevalence of onychomycosis and dermatophytosis in a selected high risk group, consisting of male boarding school residents. A total of 410 males inhabiting two houses were evaluated by two dermatologists. In cases of clinical suspicion, appropriate samples were taken for direct microscopy and culture. The results showed that the prevalences of tinea pedis (athletes foot) and pure pedal onychomycosis were 51.5% (n:211) and 4.4% (n:18), respectively. Thirty cases of those with tinea pedis were complicated by toenail onychomycosis. Tinea cruris was present only in five cases with tinea pedis. Interestingly 71.1% of those with tinea pedis and 45.8% of those with onychomycosis, associated with or without tinea pedis were unaware of their diseases. The most common fungal isolate was Trichophyton rubrum (76.6%) followed by Epidermophyton floccosum (11.6%), T. interdigitale (10.55%). Approximately one third of the cultures from nail specimens yielded pure growths of nondermatophyte moulds or Candida albicans. In conclusion, we found unexpectedly high prevalences of occult athletes foot and toenail onychomycosis among the male residents of student houses. Our results indicate that health-care workers of such common boarding-houses should be more aware of clinical and subclinical dermatophyte infections and onychomycosis, and have more active approaches to educational measures and management strategies to prevent further infections. To our knowledge, this is the first epidemiologic study on the prevalences of dermatophytosis and onychomycosis in boarding-houses from Turkey.