Physiological changes in them in post-stress emerging <Emphasis Type="Italic">Ctenanthe setosa</Emphasis> plants under drought conditions

The capability of Ctenanthe setosa (Rosc.) Eichler (Marantaceae), pre-exposed to severe drought stress, of adaptation to a new drought conditions was investigated. C. setosa unstressed plants were exposed to drought period of 70 days. These plants were named as primary-stress plants (PS). They were trimmed, and new plants were produced from their rhizomes. New growing plants were named as post-stress emerging (PSE) plants. It was observed that leaf area and petiole length of PSE plants were reduced, as compared to unstressed plants. When PSE plants were exposed to a second drought-stress cycle, it was determined that the degree of their leaf rolling was higher but their relative water content (RWC) was less than these parameters of PS plants during drought period. However, at the 81% rolling degree, RWC in PSE plants was higher than in PS plants. Consequently, it can be said that the PSE plant were more resistant to a new drought stress than unstressed and PS plants. In the leaves of PSE plants, which were exposed to a second drought-stress period, the content of soluble protein decreased in the early period of drought, but increased in the later periods. Also, the content of reducing sugar in PSE plants gradually decreased during the stress period. Proline content increased markedly during drought period, whereas peroxidase activity increased up to the 60th day and then decreased. This text was submitted by the authors in English.     

P53 related apoptosis in kidneys in CO2 pneumoperitoneum rat model: an immunohistochemical study

Laparoscopic surgery techniques have been increasingly preferred to classic laparotomy by surgeons since 1987. However, this method may have some side effects on different intraabdominal organs including kidneys. The aim of this study is to evaluate the effects of different pressures of CO₂ on p53 related apoptosis in kidneys. Totally 24 male rats were divided into four equal groups. CO₂ is insufflated into rats’ intraabdominal cavity in two different pressures of 10 and 20 mmHg during 1 h. However, in sham group, only cannula was inserted, but no gas was insufflated. After 1 h, 30 min reperfusion was applied. At last, the kidneys were excised and p53 expression and apoptosis were evaluated immunohistochemically. All the data revealed that the number of apoptotic cell in kidney’ tubular cells significantly increases in proportion to CO₂ pressure level. On the other hand, p53 expression was detected only in the highest pressure. Because the low CO₂ pressured group’ rats had no p53 expression in kidneys, we suggest that this method can be safely used for abdominal surgery. At the same time, increasing in the number of apoptotic cells parallel to pressure also suggest that CO₂ pressure level and application time are very important parameters during CO₂ pneumoperitoneum.     

Development of Malignant Ventricular Arrhythmias in a Young Male with WPW Pattern

In Wolff-Parkinson-White Syndrome (WPW), presence of accessory pathways causes various tachyarrhythmias that lead to different symptoms and clinical conditions in patients. Atrial fibrillation is observed in about 20-30% of this group of patients. Life threatening malignant ventricular arrhythmias and sudden cardiac deaths are observed in patients having rapid conduction in accessory pathways and short antegrade refractory periods (<250 msn). We present a WPW syndrome case that presented to the emergency service with narrow QRS tachycardia and later developed malignant ventricular arrhythmia.     

The effects of exogenous polyamines on some biochemical changes during drought stress in Ctenanthe setosa (Rosc.) Eichler

Morphological and biochemical changes in plant cells are known as important events for adaptation to stress. In this study, in Ctenanthe setosa leaves to which polyamines were applied during drought stress, changes in the activity of peroxidase, reducing sugar, proline and soluble protein levels were investigated. The three common polyamines, putrescine, spermidine and spermine were exogenously treated through the leaves. The polyamines were sprayed onto the leaves at 5 x 10(-5) M. In the leaves to which polyamines were applied the peroxidase activity decreased, soluble protein increased. Also, it was determined that putrescine and spermidine caused an increase in the amount of proline and in reducing sugar. However, increase was not observed in the leaves to which spermine was applied. In addition, we observed an increase in the activity of peroxidase, proline and reducing sugar levels, and a decrease in soluble protein level in the control ones and the leaves to which polyamines were applied during drought stress. As a result, the effect of polyamine on leaf rolling may be explained through the contribution to osmotic adjustment of the increase in proline, reducing sugar and soluble protein contents.     

Antioxidative role of melatonin in organophosphate toxicity in rats

Previous studies revealed that oxidative stress could be an important component of the mechanism of organophosphate (OP) compound toxicity. The aim of the present study was to investigate both prophylactic and therapeutic effects of melatonin against fenthion-induced oxidative stress in rats. Therefore, we determined the changes in the levels of reduced glutathione (GSH) and malondialdehyde (MDA) in the whole blood, brain, pectoral muscle, liver, lung, heart, kidney, pancreas, and jejunum. Also, the changes in the levels of serum nitrite and nitrate, ascorbic acid, retinal, b-carotene, and ceruloplasmin were measured. In addition, activities of enzymatic antioxidants superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT) in erythrocyte of normal and experimental animals were measured. It was found that fenthion administration increased the levels of MDA in all tissues and decreased or increased the levels of GSH in some tissues. In comparison to nitrate, nitrite and ascorbic acid levels in the serum of experimental groups, there was no significant difference between groups. However, fenthion toxicity led to decrease in retinol and β-carotene levels; melatonin administration significantly prevented this decrease. Serum ceruloplasmin level was increased due to fenthion administration, but prophylactic and therapeutic melatonin administration inhibited the increase in ceruloplasmin level of serum. There was no significant change in SOD levels in melatonin-administered groups. Melatonin modulates the fenthion-induced changes in the activities of GPx and CAT. In conclusion, the results of the current study revealed that OP toxicity, induced by fenthion, activated oxidant systems in all antioxidant systems in some tissues. Melatonin administration led to a marked increase in antioxidant activity and inhibited lipid peroxidation in most of tissues.     

Oxidative and nitrative stress markers in glaucoma

Glaucoma is a progressive optic neuropathy and is the leading cause of blindness in the United States and other industrialized countries. Elevated pressure in the eye is a risk factor for glaucoma and indeed experimental studies of induced pressure elevation in nonhuman primate's results in typical glaucomatous optic nerve damage. However, normal intraocular pressure can also lead to loss of vision in glaucoma. Although the initiating causes leading to glaucoma are unknown, oxidative and nitrative stress appears to play a role in the progressive neuronal death that is characteristic of glaucomatous optic nerve damage. Increased markers of oxidative stress that have been reported in glaucoma include protein nitrotyrosine, carbonyls in proteins, lipid oxidation products and oxidized DNA bases. Studies have also highlighted the role of nitric oxide in glaucoma by reporting the presence of inducible nitric oxide synthase in the iris-ciliary body, retina and in the glaucomatous optic nerve head of experimental rat models. This review discusses the role of reactive oxygen and nitrogen species in the pathogenesis of glaucoma and examines the relevance of antioxidants in neurodegeneration associated with the disease. It is concluded that oxidative and nitrative stress have a pathogenic role in glaucoma.     

Neuroprotective Effect of Etomidate in the Central Nervous System of Streptozotocin-Induced Diabetic Rats

It is well known that hyperglycaemia due to diabetes mellitus leads to oxidative stress in the central nervous system. Oxidative stress plays important role in the pathogenesis of neurodegenerative changes. In the present study we investigated the possible neuroprotective effect of etomidate against streptozotocin-induced (STZ-induced) hyperglycaemia in the rat brain and spinal cord. A total of 40 rats were used in this study. Rats were divided into four groups: sham-control, diabetic, diabetic-etomidate treated and vehicle for etomidate treatment group. Diabetes mellitus was induced by a single injection of streptozotocin (60 mg/kg body weight). Three days after streptoztocin injection, etomidate (2 mg/kg) was injected intraperitoneally for etomidate group and lipid emulsion (10%) for vehicle group was injected with corresponding amount intraperitoneally every day for 6 weeks. Six weeks after streptozotocin injection, seven rats from each group were killed and brain, brain stem and cervical spinal cord were removed. The hippocampus, cortex, cerebellum, brain stem and spinal cord were dissected for the biochemical analysis (the level of malondialdehyde [MDA], total nitrite, reduced glutathione [GSH], and xanthine oxidase [XO] activity). STZ-induced diabetes resulted in significantly elevation of MDA, XO and nitrite levels in the hippocampus, cortex, cerebellum, brain stem and spinal cord of the rats (P < 0.05) while etomidate treatment provided significantly lower values (P < 0.05). This study demonstrated that etomidate have neuroprotective effect on the neuronal tissue against the diabetic oxidative damage.