Nevin Ilhan

Antioxidant vitamin levels in term and preterm infants and their relation to maternal vitamin status.

BACKGROUND Lipid peroxidation plays a vital role in the pathogenesis of many neonatal complications. Preterm babies are especially predisposed to lung diseases and retinopathy, probably due to a deficiency in their antioxidant systems. Vitamins E, A, and C are part of the natural antioxidant defense systems. We aimed to determine the levels of vitamins E, A, and C in maternal and cord blood plasma of term and preterm infants and to investigate the relationships between these levels. METHODS In the present study we determined vitamin E, A, and C levels in the umbilical cord blood of term (n = 30) and preterm (n = 22) infants and their mothers by HPLC. Blood samples were taken during delivery. RESULTS Levels of lipid soluble antioxidant vitamin E and A in cord blood were lower than maternal values (p <0.01, p <0.05, respectively). Conversely, the level of water-soluble vitamin C was higher in cord blood than in maternal level (p <0.05). Significantly higher levels of vitamins E, A, and C were found in term babies as compared with those born preterm (p <0.05). CONCLUSIONS There was a positive correlation between maternal and cord blood levels of vitamins E and A (r = 0.775, r = 0.725, respectively). In conclusion, preterm babies have fewer lipid-soluble antioxidant vitamins in their serum compared to term infants. Therefore, it is possible to postulate that preterm infants are more susceptible to oxidative stress.

Vitamin D deficiency and reduced bone mineral density in multiple sclerosis: effect of ambulatory status and functional capacity

Multiple sclerosis (MS) is a chronic disease and a major cause of disability in young adults. The aims of this study were to assess bone mass in patients with MS in comparison to healthy age- and sex-matched controls, and to evaluate factors influencing bone mineral density (BMD), and the relationship of the pain threshold at peripheral and axial sites with BMD in MS. Thirty-one patients with MS and 30 matched healthy controls participated in the study. The Kurtzke expanded disability status scale (EDSS) and the functional independence measure (FIM) were used to scale disability, mobility, and functional status. Serum 25(OH) vitamin D levels were measured. BMD was measured using dual X-ray absorptiometry (DXA). MS patients had significantly lower BMD at the lumbar spine (L2-L4) and femur trochanter compared to the matched controls. BMD of the lumbar spine was nearly 1 SD lower in MS patients compared with the healthy reference population (Z scores). MS patients had significantly lower vitamin D levels (17.3 ng/ml vs 43.1 ng/ml; P < 0.001) compared to controls, and 19 patients (61%) had a serum level of vitamin D that was less than 20 ng/ml. EDSS scores in the patients were inversely correlated with proximal femur BMD but not with spinal BMD. There was a negative correlation with the cumulative steroid dose and BMD only for femur trochanter BMD. Total myalgia scores for paravertebral muscles correlated significantly with spinal BMD. In conclusion, BMD is significantly lower in MS patients than in healthy controls, vitamin D deficiency is prevalent in MS, and ambulatory status is a determinative factor for osteoporosis in MS. Patients should be encouraged to have adequate sunlight exposure and to increase their mobility. Specific strengthening exercises for hip and back muscles in MS patients would have a substantial impact on bone density, osteoporosis, fracture risk, and mobility.

The changes of trace elements, malondialdehyde levels and superoxide dismutase activities in pregnancy with or without preeclampsia.

OBJECTIVES Increased free radical activity and lipid peroxidation may be implicated in the pathogenesis of preeclampsia. This study was initiated to assess antioxidant enzyme and trace metalss status in preeclampsia. DESIGN AND METHODS The comparison was made between the pregnant women with or without preeclampsia and healthy controls in this study. Samples were obtained from 24 normal nonpregnant (controls), 30 normal pregnant and 21 preeclamptic women in the third trimester. Lipid peroxidation end product, malondialdehyde (MDA), free radical scavenging enzyme activity, superoxide dismutase (SOD) and serum zinc (Zn), copper (Cu) levels were measured in either plasma/serum or erythrocytes of patients. Data were analyzed statistically using Students t-test. RESULTS In the preeclamptic group malondialdehyde, Cu levels were significantly increased, while Zn and SOD levels were significantly decreased compared to normal control group and healthy pregnant women. CONCLUSIONS Our findings give support that radical scavenging SOD is consumed by the increased lipid peroxidation in preeclampsia. This data may indicate an involvement of free radicals in the pathophysiology of preeclampsia. This study suggests a relationship between increased MDA, Cu levels and decreased SOD, Zn levels in pregnancy and preeclampsia.

A comparison of leptin and ghrelin levels in plasma and saliva of young healthy subjects

In the last 10 years, saliva has been increasingly used as a diagnostic fluid and in predictions of disease progression. Leptin and ghrelin are synthesized in several tissues including the salivary glands. The action of ghrelin is antagonistic to that of leptin. This study was undertaken to measure and compare the saliva ghrelin-leptin and plasma ghrelin-leptin levels in healthy young subjects. In 30 healthy subjects, after an overnight fast, saliva and plasma leptin levels were measured using the ELISA method while saliva and plasma immunoreactive ghrelin levels were measured using a commercial radioimmunoassay (RIA). The latter uses 125I-labeled bioactive ghrelin as a tracer and a rabbit polyclonal antibody raised against full-length octanoylated human ghrelin (Phoenix, Europe, Karlsruhe, Germany). The results of this investigation revealed that saliva leptin levels (6.19+/-2.10 microg/l) were lower than plasma levels (7.39+/-3.23 microg/l) while saliva ghrelin levels (188.5+/-84.7 pg/ml) were higher than plasma levels (126.4+/-38.5 pg/ml), when male and female subjects were considered together. Saliva leptin levels (5.93+/-1.94 microg/l) were lower than plasma levels (6.22+/-2.92 pg/ml) while saliva ghrelin levels (190.3+/-80.2 pg/ml) were higher than plasma levels (120.4+/-35.7 pg/ml) in young males. Saliva leptin levels (6.47+/-2.29 microg/l) were lower than plasma levels (8.73+/-3.14 microg/l) while saliva ghrelin levels (183.2+/-90.2 pg/ml) were higher than plasma levels (129.3+/-42.8 pg/ml) in young females, and both saliva and plasma leptin levels were slightly lower in male subjects in comparison with female subjects. Also, Immunohistochemistry study indicated that ghrelin positivity was found in ductus epithelium of salivary gland. We have demonstrated for the first time that saliva ghrelin levels were higher than in plasma while saliva leptin levels were almost the same as in plasma. Measurements of ghrelin and leptin in saliva is non-invasive, simple, and generally much preferred by patients and thus may be an acceptable alternative to plasma sampling.

Effect of thinner inhalation on lipid peroxidation and some antioxidant enzymes of people working with paint thinner.

Paint thinner is a commonly used industrial solvent with considerable potential for abuse by inhalation. Paint thinner is taken into the body by inhalation or by contact with the skin. Paint thinner is oxidized gradually by cytochrome P450‐dependent monooxygenase and consequently free radicals are produced. In the present study we measured plasma malondialdehyde (MDA, a product of lipid peroxidation) levels as an indicator of oxidative damage and activity levels of antioxidant enzymes gluthatione peroxidase (GSH‐Px) and superoxide dismutase (SOD) in erythrocytes of a group of people (n = 18) working with paint thinner. The control group was composed of 18 healthy adults. There was a statistically significant (p < 0·001) increase in MDA (2·0±0·7 nmol ml‐1) and GSH‐Px (86·5±16·6 U g‐1 Hb) activity levels in people working with paint thinner compared with control subjects (MDA: 1·0±0·3 nmol ml‐1; GSH‐Px: 53·9±14·5 U g‐1 Hb). Similarly, there was also an increase (p < 0·05) in the SOD levels (1079±214·6 U g‐1 Hb) of people working with paint thinner compared with controls (953·3±46·7 U g‐1 Hb). Based on our results, it can be concluded that paint thinner inhalation may increase lipid peroxidation and consequently induce antioxidant enzymes. Copyright

The effects of low dose leukotriene receptor antagonist therapy on airway remodeling and cysteinyl leukotriene expression in a mouse asthma model

Airway structural changes that occur in patients with asthma in response to persistent inflammation are termed airway remodeling. The cysteinyl leukotrienes (LTC4, D4 and E4) are known to play important roles in the pathobiology of asthma. To evaluate the effect of low dose montelukast (MK) on the development of airway remodeling using a chronic murine model of allergic airway inflammation with subepithelial fibrosis, BALB/c mice, after intraperitoneal ovalbumin (OVA) sensitization on days 0 and 14, received intranasal OVA periodically on days 14-75. MK treated mice received montelukast sodium intraperitoneally on days 26-75. The OVA sensitized/challenged mice developed an extensive eosinophil cell inflammatory response, goblet cell hyperplasia, mucus occlusion, and smooth muscle hypertrophy of the airways. In addition, in OVA sensitized/challenged mice, dense collagen deposition/fibrosis was seen throughout the lung interstitium surrounding the airways, blood vessels, and alveolar septae. The cysteinyl leukotriene 1 (CysLT1) receptor antagonist, MK significantly reduced the airway eosinophil infiltration, goblet cell hyperplasia, mucus occlusion, and lung fibrosis except airway smooth muscle hypertrophy in the OVA sensitized/challenged mice. The OVA sensitized/challenged mice had significantly increased epithelial desquamation compared with control mice. MK markedly reduced epithelial desquamation of airways in OVA/MK treated animals compared with OVA sensitized/challenged mice. MK treatment did not affect the levels of CysLT in lung tissue. Our results show that the important role of cysteinyl leukotrienes in the pathogenesis of asthma. Lower dose of CysLT1 receptor antagonism has a significant anti-inflammatory effect on allergen-induced lung inflammation and fibrosis but not airway smooth muscle hypertrophy in an animal model of asthma.

Evaluation of the anti‐inflammatory effect of infliximab in a mouse model of acute asthma

Background and objective:  To evaluate the potential role of anti‐tumour necrosis factor (TNF)‐α mAb (infliximab) on the inflammatory response in a mouse model of acute asthma.

Serum Levels of Leptin and Homocysteine in Women with Polycystic Ovary Syndrome and Its Relationship to Endocrine, Clinical and Metabolic Parameters

We examined the relationship between endocrine, clinical and metabolic parameters in 35 women (mean age 27.3 years) with polycystic ovary syndrome (PCOS) and 30 age- and body mass index-matched normal ovulatory women. In PCOS women, serum leptin, homocysteine, insulin, insulin-like growth factor-1, insulin-like growth factor binding protein-3 levels and the insulin resistance index (HOMA-IR) were significantly higher, while sex hormone-binding globulin and high-density lipoprotein cholesterol levels were lower compared with healthy women. Serum luteinizing hormone (LH), estradiol (E2), androstenedione, testosterone and dehydroepiandrosterone sulphate levels were found to be significantly higher in PCOS women compared with healthy women. The levels of E2, LH and testosterone were positively correlated with leptin levels in PCOS women. Similarly, androstenedione levels and HOMA-IR were positively correlated with homocysteine levels and insulin levels were positively correlated with LH. We conclude that increased homocysteine levels, hyperandrogenaemia, insulin resistance and impaired lipid metabolism contribute to the risk of premature atherosclerosis in PCOS women.

The Protective Effect of Alpha-Lipoic Acid against Oxidative Damage in Rabbit Conjunctiva and Cornea Exposed to Ultraviolet Radiation

Purpose: The purpose of this study was to determine the protective effect of α-lipoic acid against oxidative damage in rabbit conjunctiva and cornea exposed to ultraviolet radiation. Methods: 20 rabbits weighing 2,500– 3,000 g were used, and we divided them into 4 groups with 5 randomly selected rabbits. The rabbits were exposed to 2 J/cm2/h of ultraviolet A radiation (UVA) in the range of 320–405 nm for 12 h per day within 90 days. The control group did not undergo any procedure, the UVA group was only exposed to UVA radiation. The PUVA group was treated with 8-methoxypsoralen and UVA. The α-lipoic acid group was administered 8-methoxypsoralen + UVA + α-lipoic acid. At the end of 90 days, the rabbits were killed by decapitation, and the eyes were enucleated. Both eyes of each rabbit were used for biochemical evaluation. Conjunctival and corneal free malondialdehyde (MDA), glutathione peroxidase (GSH-PX) and superoxide dismutase (SOD) levels were compared among the groups. Results: Conjunctival free MDA levels were lower in the α-lipoic acid group compared with the UVA and PUVA groups (p < 0.05, p < 0.001, respectively). Both conjunctival SOD levels (p < 0.05, p < 0.01, respectively) and conjunctival GSH-PX levels (p < 0.01, p < 0.001, respectively) were higher in the α-lipoic acid group compared with other groups. Corneal free MDA levels were lower in the α-lipoic acid group compared with the UVA and PUVA groups (p < 0.01, p < 0.001, respectively). Both corneal SOD levels (p < 0.01, p < 0.01, respectively) and corneal GSH-PX levels (p < 0.01, p < 0.01, respectively) were higher in the α-lipoic acid group compared with the other groups. Conclusion: α-Lipoic acid which is considered as potent antioxidant protects the eye from the damaging effect of ultraviolet exposure.

Free radicals and scavenging enzymes in chronic tonsillitis

OBJECTIVE: This study aimed to define the relationship between chronic tonsillitis and levels of malondialdehyde and superoxide dismutase in free radical and antioxidant forms. It is suggested that free oxygen radicals may play a role in chronic tonsillitis. MATERIALS AND METHODS: One hundred twenty-four patients were enrolled in the study. Tonsillectomy was performed via the usual dissection-snare method. Venous blood was taken preoperatively and at 2 weeks postoperatively. Blood samples and tonsil specimens were evaluated for malondialdehyde and superoxide dismutase analysis. RESULTS: The levels of malondialdehyde and superoxide dismutase in plasma were compared preoperatively and postoperatively, and there were statistically significant differences between these levels (P < 0.05). In contrast, the levels of malondialdehyde and superoxide dismutase in tonsil tissue were not correlated with the plasma levels of malondialdehyde and superoxide dismutase in pretonsillectomy and posttonsillectomy terms (P > 0.05). CONCLUSION: The presence of malondialdehyde and superoxide dismutase in plasma and tonsil tissue reinforces the involvement of oxidative stress in the pathophysiology of chronic tonsillitis.