Asymmetric dimethylarginine is not a good predictor of ischemia using myocardial perfusion scintigraphy.

BACKGROUND/AIM: Asymmetric dimethylarginine (ADMA) plays role in the pathogenesis of coronary artery disease and related mortality and morbidity through a number of mechanisms. We hypothesized that plasma ADMA levels would be increased in the presence of reversible ischemia as measured by GATED single photon emission computed tomography (SPECT) myocardial perfusion scintigraphy (MPS). MATERIALS AND METHODS: Fasting i.v. blood samples were drawn before testing. All patients underwent 99mTc-sestamibi GATED SPECT MPS with a one-day stress-rest protocol; the images were visually analyzed. Post-stress GATED parameters, including ejection fraction, end systolic and end diastolic volumes, and automatic stress defect scores, were recorded. RESULTS: The plasma ADMA levels were higher in the ischemic group than in the non-ischemic group (0.46 ± 0.19 vs. 0.40 ± 0.15; P = 0.016). Plasma ADMA levels (odds ratio [OR] = 13.5; 95% confidence interval [CI] = 1.7-109.01; P = 0.015) and sex (OR = 2.49, 95% CI = 1.18-5.26; P = 0.017) were independent predictors of ischemia. There was no linear correlation between plasma ADMA levels and both the GATED SPECT and stress test parameters. CONCLUSION: Our data support the hypothesis that increased baseline ADMA levels are independently related with the presence of reversible ischemia.

Serum visfatin and omentin levels in slow coronary flow.

OBJECTIVE: The adipocytokines visfatin and omentin have a direct effect on inflammation and endothelial injury. The expression of visfatin is closely associated with the expression of proinflammatory cytokines. Omentin has an anti-inflammatory effect and is inversely associated with coronary artery disease (CAD). The slow coronary flow phenomenon is an angiographic finding characterized by delayed distal vessel opacification in the absence of significant epicardial coronary disease. The pathophysiology of SCF has not been clearly identified, although multiple abnormalities including endothelial dysfunction, atherothrombosis and inflammation have been reported. However, the relationship between visfatin, omentin and SCF is still unknown. In this study, we aimed to investigate the relationship of these adipocytokines with SCF. METHODS: The study included slow coronary flow (n=45) and normal coronary flow (n=55) subjects, according to the corrected TIMI frame count, who underwent angiography in the catheterization laboratory of Duzce University. Statistical analyses were performed with SPSS version 12. RESULTS: Visfatin levels were significantly higher in patients with SCF than in controls (p<0.001). Plasma omentin levels were lower in the SCF group than in controls, although without statistical significance. Visfatin, gender and platelet count were significant predictors of SCF in multivariate logistic regression analysis (OR 0.748, 95% CI 0.632-0.886, p=0.01; OR 30.016, 95% CI 4.355-206.8, p=0.01; OR1.028, 95% CI 1.006-1.050, p=0.011, respectively). CONCLUSION: Adipocytokines such as visfatin and omentin may play a role in the pathogenesis of coronary slow flow.

Association of omentin Val109Asp polymorphism with coronary artery disease.

OBJECTIVE: Coronary artery disease (CAD) is the most important morbidity and mortality disease in the world. It is also one of the leading causes of death in Turkey. Omentin, a recently found adipocytokine, is reported to regulate insulin sensitivity. It has anti-inflammatory properties and is inversely associated with CAD. Omentin gene polymorphism in patients with CAD has not been studied yet. The aim of this study is to investigate the relationship between omentin Val109Asp polymorphism and CAD. METHODS: This is an observational study on genetic association. 157 consecutive patients who had undergone coronary angiography were included in the study. Seventy-five of them had CAD and the rest serves the control group. Val109Asp polymorphism was analyzed and compared. Chi-square test was used in comparison of genotype frequencies, whereas ANOVA and chi-square tests were used in comparison of clinical characteristics according to the genotypes. RESULTS: There was no significant difference between CAD patients and control subjects regarding omentin Val109Asp polymorphism. However, a 2.5 fold increase in Val/Val (homozygous mutant) genotype was detected in patients with CAD. The OR (80% Cl) for Val/Val genotype was 3.46 (1.14-10.49). CONCLUSION: Although no significant difference was detected regarding omentin Val109Asp polymorphism, Val/Val genotype frequency was found to be more in patient group than control group. In conclusion, it may be speculated that Val/Val genotype increases the tendency for CAD, but this experiment should done with larger population to clarify this issue.

N-Acetyl cysteine and erdosteine treatment in acetaminophen-induced liver damage.

OBJECTIVE: This study is aimed to investigate the efficacy of erdosteine usage in acetaminophen-induced liver damage and to compare it with N-acetyl cysteine (NAC) in the treatment and prevention of liver toxicity due to overdose of acetaminophen. METHODS: The rats were separated into the following six groups of seven rats each: control group; acetaminophen (1 g/kg, orally); acetaminophen (1 g/kg, orally) + erdosteine (150 mg/kg/day, orally); acetaminophen (1 g/kg, orally) + NAC (140 mg/kg loading dose, followed by 70 mg/kg, orally); NAC (140 mg/kg loading dose, followed by 70 mg/kg, orally); erdosteine (150 mg/kg/kg, orally), subsequently. In all the groups, potential liver injuries were evaluated using biochemical and hematological analyses, oxidant-antioxidant parameters and histopathological parameters. RESULTS: In acetaminophen-treated group, levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), total oxidant status (TOS) in the blood, prothrombin time (PT) and international normalized ratio (INR) were significantly increased when compared with controls. However, total antioxidant capacity (TAC) and glutathione (GSH) levels were decreased in group treated with acetaminophen, when compared with control group. Levels of AST, ALT and TOS, PT and INR were decreased in groups treated with NAC and erdosteine after acetaminophen administration, but the levels of TAC and GSH were increased. Histopathological improvements were observed in the groups treated with NAC and erdosteine after acetaminophen administration. CONCLUSION: The present study demonstrated that, in the prevention of liver damage induced by acetaminophen intoxication, an early treatment with a single dose of erdosteine was beneficial instead of NAC administration.

Resistin predicts ischemia in myocardial perfusion scintigraphy.

UNLABELLED: Aim: Resistin plays a role in the pathogenesis of coronary artery disease and is related to mortality and morbidity through a number of mechanisms. We hypothesize that plasma resistin levels are increased in the presence of ischemia, as measured by GATED single- photon emission computed tomography myocardial perfusion scintigraphy (SPECT MPS), in comparison with nonischemic subjects. MATERIALS AND METHODS: Fasting intravenous blood samples of patients were drawn before a stress test. An ELISA kit was used for the assays. All patients underwent a technetium 99m-sestamibi GATED SPECT MPS study with a 1-day stress-rest protocol. Images were analyzed visually and patients were assessed as ischemic or nonischemic. Resistin levels were presented as medians (25th-75th percentiles) and were compared using the Mann-Whitney U test. RESULTS: Plasma resistin levels were higher in the ischemic group (n = 47) than in the nonischemic group (n = 67) [9.04 pmol/L (6.27-11.8 µmol/L) vs. 3.56 µmol/L (0.39-7.93 pnol/L), respectively; P < 0.001). We showed that plasma resistin levels (OR = 1.26, 95% CI: 1.13-1.41; P < 0.001) and METs (OR = 0.82, 95% CI: 0.70-0.92; P = 0.021) were independent predictors ofischemia. No linear correlation was found between plasma resistin levels and GATED SPECT or stress test parameters. CONCLUSION: Increased baseline resistin levels are independently related to presence of ischemia but are not related to the extent or severity of ischemia, or other functional parameters such as poststress ejection fraction, end systolic, and end diastolic volumes.

Interleukin-6 levels in tension headache patients.

OBJECTIVE: Cytokines are pain mediators in neurovascular inflammation. This study examined interleukin 6 (IL-6) levels in the serum of tension-type headache (TTH) patients, to determine if inflammation plays a role in the pathogenesis of this condition. METHODS: Serum IL-6 levels were studied in 42 patients and 37 healthy controls from the same region. Of the patients, 20 (47.6%) experiencing TTH less than 15 days per month were placed in episodic tension-type headache (ETTH) group, and 22 (52.3%) with TTH more than 15 days per month were placed in chronic tension-type headache (CTTH) group. RESULTS: The IL-6 level was significantly higher in the patients than in the controls. The IL-6 level of CTTH patients was higher than the controls (P<0.01). The IL-6 level was similar between ETTH and CTTH patients. Correlation analysis revealed a positive relationship only between age and IL-6 level in the patients. CONCLUSIONS: CTTH and ETTH patients had an elevated serum IL-6 level compared with controls. Therefore, we believe that IL-6 may be involved in pain induction or inflammatory mechanisms in TTH. Furthermore studies of the possible connection between chronicity of headaches and cytokine levels are needed.

Effects of Urtica dioica on hepatic ischemia-reperfusion injury in rats.

OBJECTIVES: To evaluate the effects of Urtica dioica on hepatic ischemia-reperfusion injury. METHODS: Thirty adult male Wistar albino rats were divided into three groups: sham group (group 1), control group (group 2), and Urtica dioica group (group 3). All the rats were exposed to hepatic ischemia for 60 min, followed by 60 min of reperfusion. In group 2, a total of 2 ml/kg 0.9% saline solution was given intraperitoneally. In group 3, a total of 2 ml/kg Urtica dioica was given intraperitoneally. At the end of the procedure, liver tissue and blood samples were taken from all rats. Serum aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, ceruloplasmin, catalase, paraoxonase, arylesterase, and lipid hydroperoxide levels were measured. Liver tissue histopathologies were also evaluated by light microscopy. RESULTS: Serum aspartate aminotransferase, alanine aminotransferase and lactate dehydrogenase levels were significantly higher in group 2 than in group 1, and significantly lower in group 3 than in group 2. Also, group 2 had higher serum lipid hydroperoxides and ceruloplasmin levels but lower catalase, paraoxonase, and arylesterase levels than group 1. In group 3, serum lipid hydroperoxides and ceruloplasmin levels were significantly lower, and catalase, paraoxonase, and arylesterase levels were higher than those in group 2. Histopathological examination showed that liver tissue damage was significantly decreased in group 3 compared with group 2. CONCLUSIONS: Urtica dioica has a protective effect on the liver in hepatic ischemia-reperfusion-injured rats.

Effects of Urtica dioica on hepatic ischemia-reperfusion injury in rats

OBJECTIVES: To evaluate the effects of Urtica dioica on hepatic ischemia-reperfusion injury. METHODS: Thirty adult male Wistar albino rats were divided into three groups: sham group (group 1), control group (group 2), and Urtica dioica group (group 3). All the rats were exposed to hepatic ischemia for 60 min, followed by 60 min of reperfusion. In group 2, a total of 2 ml/kg 0.9 percent saline solution was given intraperitoneally. In group 3, a total of 2 ml/kg Urtica dioica was given intraperitoneally. At the end of the procedure, liver tissue and blood samples were taken from all rats. Serum aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, ceruloplasmin, catalase, paraoxonase, arylesterase, and lipid hydroperoxide levels were measured. Liver tissue histopathologies were also evaluated by light microscopy. RESULTS: Serum aspartate aminotransferase, alanine aminotransferase and lactate dehydrogenase levels were significantly higher in group 2 than in group 1, and significantly lower in group 3 than in group 2. Also, group 2 had higher serum lipid hydroperoxides and ceruloplasmin levels but lower catalase, paraoxonase, and arylesterase levels than group 1. In group 3, serum lipid hydroperoxides and ceruloplasmin levels were significantly lower, and catalase, paraoxonase, and arylesterase levels were higher than those in group 2. Histopathological examination showed that liver tissue damage was significantly decreased in group 3 compared with group 2. CONCLUSIONS: Urtica dioica has a protective effect on the liver in hepatic ischemia-reperfusion-injured rats.

IL-6 levels in migraine patients receiving topiramate.

There is considerable evidence suggesting that cytokines play important roles in pain and in mediating neurovascular inflammation associated with migraine headaches. Although consensus exists to recommend topiramate (TPM) for migraine prevention, the mechanism of action in this regard is unknown. We measured serum interleukin-6 (IL-6) levels in 66 migraine patients. Of these patients, 23 (34.9%) were taking TPM for migraine, and 43 (65.1%) were not. The IL-6 levels were compared with those of healthy controls without migraine, from the population living in the same region. The mean IL-6 levels in migraine patients taking TPM and patients who did not were 67.06 +/- 92.09 pg/mL and 44.09 +/- 59.19 pg/mL, respectively (P > 0.05). The IL-6 levels were higher in the patients taking TPM. The IL-6 level in the controls was 8.60 +/- 7.36 pg/mL, which was significantly lower than the patient group using TPM (P = 0.001). Our results show that, although IL-6 may be involved in pain induction or inflammatory mechanisms of migraine attacks, the serum IL-6 level was not reduced in migraine patients receiving TPM therapy. In conclusion, we found high IL-6 levels in migraine patients both with and without TPM therapy, suggesting that high IL-6 levels during pain-free periods could be a conditioning factor, making patients more vulnerable to pain attacks in chronic migraine. Further studies investigating the possible mechanism of TPM in migraine are needed.

Melatonin reduces oxidative stress in the rat lens due to radiation-induced oxidative injury.

PURPOSE: The aim of this study was to evaluate the antioxidant role of melatonin against radiation-induced cataract in the rat lens after total cranial irradiation with a single 5 Gray (Gy) dose of gamma irradiation. MATERIALS AND METHODS: Twenty-eight Sprague-Dawley rats were used for the experiment.The rats were randomly divided into four equal groups. The control group did not receive melatonin or irradiation but received both 0.1 ml physiological saline intraperitoneally and sham irradiation. The irradiation (IR) group received 5 Gy gamma irradiation to the total cranium as a single dose plus 0.1 ml physiological saline intraperitoneally. The melatonin plus IR group received irradiation to the total cranium plus 5 mg/kg/day melatonin intraperitoneally. The melatonin group received only 5 mg/kg/day melatonin plus sham-irradiation. Biochemical parameters measured in murine lenses were carried out using spectrophotometric techniques. RESULTS: Lens antioxidant capacity, as measured by levels of total superoxide scavenger activity (TSSA), non-enzymatic superoxide scavenger activity (NSSA) and glutathione reductase (GRD) activity, significantly increased in melatonin, control and melatonin plus IR groups when compared with the IR group. Lens glutathione-S-transferase (GST) activity significantly increased in control and melatonin groups when compared with the IR group. Lens malondialdehyde (MDA) levels significantly increased in the IR group when compared with control, melatonin and melatonin plus IR groups. Lens TSSA and NSSA activities significantly decreased in control and melatonin plus IR groups when compared with the melatonin group. Lens GST activity significantly increased in the control group when compared with melatonin plus IR group. Lens GRD activity significantly increased in melatonin and melatonin plus IR groups when compared with control group. CONCLUSIONS: Melatonin reduces oxidative stress markers and augments anti-oxidant capacity in the rat lens.

Melkersson Rosenthal syndrome associated with ipsilateral facial, hand, and foot swelling.

Melkersson-Rosenthal syndrome is a complex neuromucocutaneous disorder. A 60-year-old woman presented with granulomatous cheilitis of the lower lip, unilateral facial paralysis, and ipsilateral facial and acral swelling. The result of histopathological evaluation in extremities and inferior lip was compatible with Melkersson-Rosenthal syndrome.

Do Turkish adults really have lower serum levels of high-density lipoprotein cholesterol?

BACKGROUND: Coronary heart disease is the leading cause of death in Turkey. The Turkish Heart Study and TEKHARF study have been carried out at various times and in different parts of Turkey and have suggested that the Turkish population has a low high-density lipoprotein-cholesterol (HDL-C) level. However, in our daily practice, mean HDL-C levels were not as low as previously reported. Here, we investigated the lipid profile, especially the HDL-C level, in the population of the Duzce region of northwest Turkey. METHODS: Serum triglyceride, total cholesterol, and HDL-C levels were measured in 674 healthy volunteers (398 women and 276 men); low-density lipoprotein cholesterol (LDL-C) levels were calculated using the Friedewald equation. RESULTS: The mean serum HDL-C level was 46.1 +/- 9.8 mg/dl in men and 53.2 +/- 10.7 mg/dl in women; these values are higher than expected based on the Turkish Heart Study. The mean serum total cholesterol level was 196.7 +/- 43.2 mg/dL in men and 198.4 +/- 43.9 mg/dL in women; the mean LDL-C level was 119.6 +/- 34.9 mg/dL in men and 118.7 +/- 34.1 mg/dL in women; and the mean serum triglyceride level was 151.4 +/- 80.9 mg/dL in men and 132.1 +/- 68.9 mg/dL in women. CONCLUSIONS: Our finding that the HDL-C level in this population was higher than the previously reported levels in Turkey indicates that HDL-C levels may not be as low as previously thought. We believe that lower HDL-C levels that were previously reported might be due to the difference between techniques of analysis, nutritional status, and percent of subjects who were fasting in the day of analysis or improper subject inclusion which did not reflect the Turkish population causing selection bias.

High serum homocysteine levels correlate with a decrease in the blood flow velocity of the ophthalmic artery in highway toll collectors.

Highway workers, such as policemen, automotive service companies, and toll collectors, are placed at risk of the accelerated atherosclerotic process, since recent studies have suggested that exposure to exhaust particles and ambient air pollution increases carotid intima-media thickness and reduces ocular blood flow velocity. Therefore, we assessed the relationship between serum homocysteine, a potential parameter for atherosclerosis, and the ocular blood flow velocity and the resistivity index in highway toll collectors. The peak systolic and end diastolic flow velocities and the resistivity index were measured in 22 toll collectors and 24 control subjects by color Doppler ultrasonography. The resistivity index, which is an indirect measure of the atherosclerotic process, was calculated: resistivity index = (peak systolic velocity - end diastolic velocity)/peak systolic velocity. Serum homocysteine levels were determined by fluorometric high-performance liquid chromatography. In the highway toll collectors, the serum homocysteine level (14.4 +/- 4.8 micromol/l; p < 0.005) and the resistivity index of the ophthalmic artery (0.741 +/- 0.015; p < 0.05) were higher and the ophthalmic blood flow velocity (33.0 +/- 3.0 cm/s; p < 0.001) was lower than those in the controls (10.6 +/- 3.1 micromol/l; 0.728 +/- 0.023; 36.8 +/- 2.2 cm/s; respectively). There were significant correlations between the serum homocysteine level and ophthalmic artery resistivity index in both highway toll collectors (p < 0.001) and controls (p < 0.005). Exposure to exhaust particles might increase the serum homocysteine level, which in turn could lead to the decreased ocular blood flow and the increased resistivity index.

Levels of ceruloplasmin, transferrin, and lipid peroxidation in the serum of patients with Type 2 diabetes mellitus.

Diabetes mellitus (DM) is a common disease affecting over 124 million individuals worldwide. DM is associated with high risk of atherosclerosis and renal, neural, and ocular damage. Increased oxidant stress has been implicated in the pathogenesis of DM. An increase in serum ceruloplasmin (Cp) levels has also been reported in Type 2 DM. Cp permits the incorporation of iron into transferrin (Trf). Trf inhibits iron ion-dependent OHo formation from H2O2. Patients with diabetes have increased levels of plasma lipid peroxidation products. In this study, we evaluated 50 patients with Type 2 DM and 21 clinically healthy subjects. Patients were divided into two groups. Group I included 29 patients without diabetic complications, Group II 21 with diabetic complications. Serum Cp, Trf, C-reactive protein (CRP), triglyceride (TG), cholesterol (Chol), and malondialdehyde (MDA) levels are studied. Serum Cp, CRP, TG, Chol, and MDA levels in diabetic patients were significantly higher than those of controls. Trf levels were significantly lower in diabetic patients than those of the controls. Cp, CRP, HbA1C, and MDA levels in Group II were significantly higher than those of Group I. Our results indicate that oxygen free radicals are formed in DM and can result in diabetic complications and that a prooxidant/oxidant imbalance is involved in the tissue injury in DM and diabetic complications.

Antioxidant status and lipid peroxidation in type II diabetes mellitus.

Diabetes Mellitus (DM), a state of chronic hyperglycaemia, is a common disease affecting over 124 million individuals worldwide. In this study, erythrocyte glutathione levels, lipid peroxidation, superoxide dismutase, catalase, and glutathione peroxidase and some extracellular antioxidant protein levels of patients with type II diabetes mellitus and healthy controls were investigated. Thirty-eight patients (21 males; with age of mean +/- SD, 53.1+/-9.7 years) and 18 clinically healthy subjects (10 males; with age of mean +/- SD, 49.3+/-15.2 years) were included in the study. Levels of erythrocyte lipid peroxidation, serum ceruloplasmin and glucose levels, HbA1C levels, and erythrocyte catalase activity were significantly increased, whereas serum albumin and transferrin levels, erythrocyte glutathione levels, and glutathione peroxidase activity were significantly decreased compared to those of controls. There was no significant difference in superoxide dismutase activity compared to controls. The results suggest that the antioxidant deficiency and excessive peroxide-mediated damage may appear in non-insulin dependent diabetes mellitus.

Effect of macrolide antibiotics on nitric oxide synthase and xanthine oxidase activities, and malondialdehyde level in erythrocyte of the guinea pigs with experimental otitis media with effusion.

Although the long-term administrations of macrolide antibiotics are effective for diffuse panbronchiolitis, otitis media with effusion (OME), and some other diseases, their mechanism of action has not been fully understood. In order to elucidate the mechanisms of possible effects of macrolide antibiotics on activities of erythrocyte nitric oxide synthase (NOS), xanthine oxidase (XO), and malondialdehyde (MDA) levels in experimental OME, we aimed to evaluate the effect of macrolide antibiotics (erythromycin, azithromycin, roxithromycin, and clarithromycin) using an experimental guinea pig otitis media model. Erythrocyte NOS, XO activities, and MDA level were measured in all groups. Erythrocyte NOS activities were significantly higher in erythromycin-, azithromycin-, roxithromycin-, and clarithromycin-treated groups than in the experimental group. Erythrocyte XO activities were significantly lower in erythromycin-, azithromycin-, roxithromycin-, and clarithromycin-treated groups than in the control group. However, erythrocyte XO activities in experimental group were significantly higher than those of control group. Erythrocyte MDA levels were significantly lower in erythromycin-, azithromycin-, roxithromycin-, and clarithromycin-treated groups than those of the experimental group. The MDA levels in erythromycin- and roxithromycin-treated groups were significantly higher than those of azithromycin-treated group. The MDA levels in azithromycin-treated group were significantly lower than those of roxithromycin-treated group. In conclusion, the present study shows that the macrolide antibiotics (erythromycin, azithromycin, roxithromycin, and clarithromycin) increase NOS activity, decrease XO activity and MDA level, which is an important indicator of oxidative stress.

Serum oxidant/antioxidant status in patients with Behçet's disease.

The aims of this study were to assess whether the increased oxidative stress in affected tissues is reflected by serum lipid peroxidation and to check for alterations in serum levels of extracellular antioxidants and antioxidant enzyme activities in patients with Behcet's disease (BD). Serum malondialdehyde (MDA) and ceruloplasmin (Cp) levels and CuZn-superoxide dismutase (CuZn-SOD) and glutathione peroxidase (GSH-Px) activities were increased, while serum transferrin (Trf) levels were diminished in patients with active ocular BD (n = 19), inactive ocular BD (n=18), and nonocular BD (n=15), compared to healthy controls (n = 20). Serum MDA levels in patients with active ocular BD and nonocular BD were significantly higher than in the inactive ocular BD group. Patients with active ocular BD also had significantly higher serum Cu-Zn SOD activities, compared to the inactive ocular BD. Erythrocyte sedimentation rate (ESR) and serum C-reactive protein (CRP) levels were higher in patients with active ocular BD, inactive ocular BD, and nonocular BD, compared to the control group. In addition, patients with active ocular BD and nonocular BD had significantly higher ESR and serum CRP levels, compared to the inactive ocular BD group. Serum albumin concentrations showed no significant differences among the BD patients and controls. The authors speculate that in BD patients, serum superoxide radicals may be dismutated to H2O2 by increased CuZn-SOD activity and the conversion of H2O2 to hydroxyl radical may be enhanced by iron, owing to diminished serum Trf; these mechanisms may contribute to the increased serum lipid peroxidation.

Effect of breast-feeding on concentration of nitric oxide in breast milk.

BACKGROUND: The effect of breast-feeding on the concentration of nitric oxide (NO) in milk was investigated in lactating mothers. METHODS: Breast milk specimens were obtained from 45 lactating women after normal delivery on postpartum days 1, 2, 3, 4 and 5. The subjects were divided into three groups: group 1, breast-feeding only; group 2, mixed feeding (breast milk by manual expression and additional formula feeds); and group 3, formula feeding only. Milk NO concentration was measured as the sum of nitrite and nitrate using the Griess reaction. RESULTS: The highest mean milk NO concentration was on day 4 in all groups, but the peak value in group 3 was significantly lower (P<0.0001) than in other groups. The milk NO concentrations of group 1 were significantly greater than those of groups 2 and 3. CONCLUSIONS: We conclude that breast-feeding increases the concentration of NO in milk.

Changes of PSA concentrations in serum and saliva of healthy women during the menstrual cycle.

This study investigated the changes of prostate specific antigen (PSA) concentrations in serum and saliva of women during the menstrual cycle. Thirty healthy volunteers (age 23-35 yr) were enrolled in the study. During the menstrual cycle, serum and saliva PSA concentrations on days 9 (follicular phase) and 14 (mid-cycle) were significantly higher than on days 4 (early follicular phase) and 21 (luteal phase). The expected changes in gonadal hormones were seen, as evidenced by significantly higher serum estradiol and progesterone concentrations during the midcycle and luteal phase, compared to the other phases of the cycle. Serum PSA concentrations were positively correlated with salivary PSA concentrations at all 4 times (days 4, 9, 14, and 21) of the menstrual cycle, but not with the serum progesterone or estrogen concentrations. This study suggests that salivary PSA, rather than being produced in the salivary gland, may reflect the serum PSA during the normal menstrual cycle.