Serap Cilaker Micili

The Effects of Dexmedetomidine on Secondary Acute Lung and Kidney Injuries in the Rat Model of Intra-Abdominal Sepsis

In the present study, the effects of dexmedetomidine on secondary lung and kidney injuries were studied in the rat model of intra-abdominal sepsis by immunohistological and biochemical examinations. We measured serum creatinine, kidney tissue malondialdehide and plasma neutrophil gelatinase-associated lipocalin levels. In order to evaluate tissue injury we determined kidney tissue mononuclear cell infiltration score, alveolar macrophage count, histological kidney and lung injury scores and kidney and lung tissue immunoreactivity scores. We demonstrated that dexmedetomidine attenuates sepsis-induced lung and kidney injuries and apoptosis in the rat model of sepsis. There is still need for comparative studies in order to determine the effects of dexmedetomidine on organ functions in early human sepsis.

Ischemic preconditioning attenuates lipid peroxidation and apoptosis in the cecal ligation and puncture model of sepsis

Sepsis and septic shock are are among the major causes of mortality in intensive care units. The lung and kidney are the organs most affected by sepsis. Evidence exists that lipid peroxidation and apoptosis may be responsible for the high mortality due to sepsis. Ischemic preconditioning (IP) is a method for the protection of tissues and organs against ischemia/reperfusion injury by reducing reactive oxygen species levels, lipid peroxidation and apoptosis. In the present study, the effects of IP were investigated in cecal ligation and puncture (CLP)-induced sepsis in rats. The three groups of animals used in the present controlled study were the sham-operated group (sham, n=7), which only underwent a laparotomy; the sepsis group (sepsis, n=7), which underwent cecal ligation and perforation; and the IP + sepsis group (IP+sepsis, n=7), which underwent CLP immediately prior to the application of three cycles of IP to the hind limb. The study was terminated at 6 h after the induction of CLP. Blood, kidney and lung tissue samples were collected for the determination of serum creatinine, blood urea nitrogen (BUN), neutrophil gelatinase-associated lipocalin (NGAL) and lung tissue malondialdehyde (MDA) levels, as well as histological examination. The serum creatinine, plasma NGAL and lung tissue MDA levels in the sepsis group were significantly increased compared with those in the sham and the IP+sepsis groups (P<0.05). Alveolar macrophage counts, histological kidney and lung injury scores, kidney (caspase 3) and lung tissue immuonreactivity (M30) scores in the sepsis group were also significantly increased compared with those in the sham and IP+sepsis groups (P<0.05). The alveolar macrophage count in the IP+sepsis group was increased compared with that in the sham group (P<0.05). In conclusion, IP inhibits lipid peroxidation and attenuates histological injury and apoptosis in the lung and kidney during sepsis.

Immunomodulatory activities of alpha lipoic acid with a special focus on its efficacy in preventing miscarriage

ABSTRACT Introduction: Alpha lipoic acid (ALA) is an essential mitochondrial co-factor and, as a free molecule, it can exert multi-level immunomodulatory functions. Both ALA and its reduced form, dihydrolipoic acid (DHLA), are believed to be able to chelate heavy metals, to regenerate essential antioxidants and to repair important molecules damaged by oxidation. The largest part of the effects of ALA/DHLA couple can be explained by a specific stimulatory activity on Nrf2-dependent gene transcription and by the inhibition of NF-kB activity. These features have prompted its use as a drug for several diseases. Areas covered: This article surveys the main features of ALA/DHLA and its therapeutic effects. Its complex and differentiated function cannot simply be reduced to anti-inflammatory, antioxidant and detoxifying action. We highlight its capability to finely modulate several physiological pathways when unbalanced. In particular, we focus our attention on pregnancy, in relation to ALA administration by oral route and by a new formulation for vaginal delivery, in patients with threatened miscarriage. Expert opinion: Future efforts should be devoted to explaining carefully ALA/DHLA mechanism of action to reactivate the physiological balance when modified during pregnancy. On the other hand, ALA safety in pregnant women and its pharmacokinetics by vaginal route, have to be studied in depth. Moreover, ALA efficacy has to be confirmed in a much larger sample of patients.

Resveratrol ameliorates 2,4-dinitrofluorobenzene-induced atopic dermatitis-like lesions through effects on the epithelium

Background. Resveratrol is a natural polyphenol that exhibits anti-inflammatory effects. The aim of this study was to investigate the effects of resveratrol treatment on epithelium-derived cytokines and epithelial apoptosis in a murine model of atopic dermatitis-like lesions. Material and Methods. Atopic dermatitis-like lesions were induced in BALB/c mice by repeated application of 2,4-dinitrofluorobenzene to shaved dorsal skin. Twenty-one BALB/c mice were divided into three groups: group I (control), group II (vehicle control), and group III (resveratrol). Systemic resveratrol (30 mg/kg/day) was administered repeatedly during the 6th week of the experiment. After the mice had been sacrificed, skin tissues were examined histologically for epithelial thickness. Epithelial apoptosis (caspase-3) and epithelium-derived cytokines [interleukin (IL)-25, IL-33, and thymic stromal lymphopoietin (TSLP)] were evaluated immunohistochemically. Results. Epithelial thickness and the numbers of IL-25, IL-33, TSLP and caspase-3-positive cells were significantly higher in group II compared to group I mice. There was significant improvement in epithelial thickness in group III compared with group II mice (p < 0.05). The numbers of IL-25, IL-33, and TSLP-positive cells in the epithelium were lower in group III than in group II mice (p < 0.05). The number of caspase-3-positive cells, as an indicator of apoptosis, in the epithelium was significantly lower in group III than in group II mice (p < 0.05). Conclusion. Treatment with resveratrol was effective at ameliorating histological changes and inflammation by acting on epithelium-derived cytokines and epithelial apoptosis.

The Regulation of Matrix Metalloproteinase Expression and the Role of Discoidin Domain Receptor 1/2 Signalling in Zoledronate-treated PC3 Cells.

Discoidin Domain Receptors (DDR1/DDR2) are tyrosine kinase receptors which are activated by collagen. DDR signalling regulates cell migration, proliferation, apoptosis and matrix metalloproteinase (MMP) production. MMPs degrade extracellular matrix (ECM) and play essential role in tumor growth, invasion and metastasis. Nitrogen-containing bisphosphonates (N-BPs) which strongly inhibit osteoclastic activity are commonly used for osteoporosis treatment. They also have MMP inhibitory effect. In this study, we aimed to investigate the effects of zoledronate in PC3 cells and the possible role of DDR signalling and downstream pathways in these inhibitory effects. We studied messenger RNA (mRNA) and protein expressions of MMP-2,-9,-8, DDR1/DDR2 type I procollagen (TIP) and mRNA levels of PCA-1, MMP-13 and DDR-initiated signalling pathway players including K-Ras oncogene, ERK1, JNK1, p38, AKT-1 and BCLX in PC3 cells in the presence or absence of zoledronate (10-100 μM) for 2-3 days. Zoledronate (100 μM) down-regulated DDR1/ DDR2, TIP mRNAs but did not change MMP-13 (collagenase-3) mRNA. However, zoledronate up-regulated MMP-8 (collagenase-2) mRNA. Zoledronate also inhibited mRNA expressions of K-Ras, ERK1, AKT-1, BCLX and PCA-1; but did not change JNK1, p38 mRNA levels. Zoledronate (100 μM) supressed DDR1/DDR2, TIP expressions; and gelatinase (MMP-2/MMP-9) expressions/activities. Conversely, zoledronate up-regulated MMP-8 expression in PC3 cells. Zoledronate down-regulates MMP-2/-9 expressions in PC3 prostate cancer cells. DDR1/DDR2 signalling and DDR-initiated downstream Ras/Raf/ERK and PI3K/AKT pathways may at least partially responsible for MMP inhibitory effect of zoledronate.

The effects of α-lipoic acid on immature rats with traumatic brain injury

Abstract Traumatic brain injury (TBI) is a leading cause of morbidity and mortality during childhood. TBI enhances formation of reactive oxygen species that cause neuron damage and apoptosis. α-Lipoic acid (LA) is a free radical scavenger and biological antioxidant. We investigated the effects of LA treatment on the parietal and prefrontal cortex, and on the hippocampal regions of the brain in 7-day-old rat pups that had been subjected to contusion injury. Forty-two male rats were divided randomly into a control group, a TBI group and a TBI + LA treated group. LA was administered 30 min after TBI through an intragastric tube once daily for 2 days. Forty-eight hours after TBI, the animals were sacrificed and tissues were examined for apoptosis and density of neurons. Terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) and active caspase-3 immunostaining were used to detect apoptosis. Glutathione peroxidase (GPx), superoxide dismutase (SOD) activity and malondialdehyde (MDA) levels also were measured. Histological evaluation showed that LA treatment significantly reduced TBI-induced neuronal death in the hippocampus, prefrontal and parietal cortex; TUNEL- and caspase-3-positive cells also were decreased in the same regions. In addition, LA administration increased GPx and SOD activity in the prefrontal cortex. It appears that LA may be beneficial for TBI in rats.

Evaluation of the effects of gonadotropin-relasing hormone antagonist (GnRH-ant) and agonist (GnRH-a) in the prevention of postoperative adhesion formation in a rat model with immunohistochemical analysis

OBJECTIVE To investigate the effects of GnRH antagonist (GnRH-ant) and agonist (GnRH-a) in the prevention of postoperative pelvic adhesions by a visual scoring system and immunohistochemical methods in a rat uterine horn model. DESIGN Controlled experimental animal study. SETTING Animal laboratory at an academic research environment. ANIMAL(S) Twenty-one Wistar albino rats. INTERVENTION(S) Rats were randomized into three groups. One week before the operation the rats received either GnRH-ant or GnRH-a or saline solution; they then underwent surgical laparotomy, and both uterine horns were traumatized by a scalpel. Three weeks later, all rats were sacrificed and extension and severity of the adhesions in each group were scored by a visual scoring system. Adhesion tissues were evaluated immunohistochemically for vitronectin and u-PAR. MAIN OUTCOME MEASURE(S) Scores of extend and severity of adhesions and staining of vitronectin and u-PAR. RESULT(S) The extent of adhesion scores were 1.85 ± 0.86, 0.78 ± 1.05, and 0.42 ± 0.64, and the severity of adhesion scores were 1.71 ± 0.91, 0.57 ± 0.85, 0.50 ± 0.75 for control, GnRH-ant, and GnRH-a groups, respectively. The extent and severity of adhesions were significantly lower in both GnRH-ant and GnRH-a groups when compared with the control group. Adhesion extent scores in the GnRH-a group were lower than in the GnRH-ant group, but this difference was not significant. vitronectin and u-PAR staining were significantly greater in both the GnRH-ant and GnRH-a groups than in the control group. CONCLUSION(S) GnRH-ant as well as GnRH-a reduced postoperative adhesion formation in a rat model. This finding was supported immunohistochemically by vitronectin and u-PAR staining.

The Role of Rac1 on Carbachol‐induced Contractile Activity in Detrusor Smooth Muscle from Streptozotocin‐induced Diabetic Rats

This study was designed to determine the role of the small GTPase Rac1 on carbachol‐induced contractile activity in detrusor smooth muscle using small inhibitor NSC 23766 in diabetic rats. Rac1 expression in bladder tissue was also evaluated. In the streptozotocin (STZ)‐induced diabetic rat model, three study groups were composed of control, diabetic and insulin‐treated diabetic subjects. The detrusor muscle strips were suspended in organ baths at the end of 8–12 weeks after STZ injection. Carbachol (CCh) (10−9–10−4 M) concentration–response curves were obtained both in the absence and in the presence of Rac1 inhibitor NSC 23766 (0.1, 1 and 10 μM). Diabetes‐related histopathological changes and Rac1 expressions were assessed by haematoxylin and eosin staining and immunohistochemical staining, respectively. CCh caused dose‐dependent contractile responses in all the study groups. Rac1 inhibitor NSC 23766 inhibited CCh‐induced contractile responses in all groups, but this inhibition seen in both diabetes groups was greater than in the control group. Histological examination revealed an increased bladder wall thickness both in the diabetes and in the insulin‐treated diabetes groups compared to the control group. In immunohistochemical staining, expression of Rac1 was observed to be increased in all layers of bladder in both diabetic groups compared to the control group. In the diabetic bladders, increased expression of Rac1 and considerable inhibition of CCh‐induced responses in the presence of NSC 23766 compared to those of the control group may indicate a specific role of Rac1 in diabetes‐related bladder dysfunction, especially associated with cholinergic mediated detrusor overactivity.

Optical coherence tomography: A potential tool to predict premature rupture of fetal membranes

A fundamental question addressed in this study was the feasibility of preterm birth prediction based on a noncontact investigation of fetal membranes in situ. Although the phenomena of preterm birth and the premature rupture of the fetal membrane are well known, currently, there are no diagnostic tools for their prediction. The aim of this study was to assess whether optical coherence tomography could be used for clinical investigations of high-risk pregnancies. The thickness of fetal membranes was measured in parallel by optical coherence tomography and histological techniques for the following types of birth: normal births, preterm births without premature ruptures and births at full term with premature rupture of membrane. Our study revealed that the membrane thickness correlates with the birth type. Normal births membranes were statistically significantly thicker than those belonging to the other two groups. Thus, in spite of almost equal duration of gestation of the normal births and the births at full term with premature rupture, the corresponding membrane thicknesses differed. This difference is possibly related to previously reported water accumulation in the membranes. The optical coherence tomography results were encouraging, suggesting that this technology could be used in future to predict and distinguish between different kinds of births.

Lipoic acid decreases peritoneal adhesion formation in a rat uterine scar model

OBJECTIVE To investigate the effects of lipoic acid in the prevention of postoperative pelvic adhesions by a visual scoring system and immunohistochemistry in a rat uterine horn model with full thickness injury. MATERIAL AND METHODS Twenty-eight female Wistar albino rats were randomised into four groups: uterine trauma control, 15 days and 30 days, and uterine trauma + lipoic acid, 15 days and 30 days. A full thickness defect was established by incising a segment of approximately 1.0 cm in length from each uterine horn, leaving the mesometrium intact. Extension and severity of the adhesions in each group were scored by a visual scoring system and evaluated immunohistochemically. RESULTS Adhesion scores were 2.00±0.81, 2.14±0.69 0.71±0.75, and 0.85±0.69 for extent and 2.28±0.48, 2.14±0.69, 0.85±0.69, and 1.14±0.69 for severity in Groups 1, 2, 3 and 4, respectively. Adhesion extent and severity were significantly less for groups treated by lipoic acid but no difference was observed between long and short administration. Both Vitronectin and u-PAR staining were significantly increased in treatment groups when compared to the control group. CONCLUSION Lipoic acid was found to be effective in reducing postoperative adhesion formation in a rat model.