Comparative analysis of thiol-disulfide homeostasis dynamics between elective cesarean section and uncomplicated vaginal delivery: insights into perinatal oxidative balance

OBJECTIVE

Thiols are organic compounds containing sulfhydryl groups that exert antioxidant effects via dynamic thiol-disulfide homeostasis. The shift towards disulfide indicates the presence of an oxidative environment. Different modes of delivery can affect thiol-disulfide homeostasis. Accordingly, we planned this research to evaluate the effects of the mode of delivery on thiol-disulfide homeostasis in both maternal serum and fetal cord blood samples.

PATIENTS AND METHODS

We conducted a prospective case-control study involving two groups: vaginal delivery (n=50) and elective cesarean section (CS) (n=45). The vaginal delivery group exclusively comprised uncomplicated term deliveries, while the CS group included pregnant individuals with scheduled cesarean deliveries due to the absence of spontaneous labor onset. Maternal serum and fetal cord blood samples were collected, and thiol-disulfide exchanges were analyzed using an automated method capable of measuring both aspects of the thiol-disulfide balance.

RESULTS

The levels of native thiol (-SH) and total thiol in both maternal serum and fetal cord blood samples were significantly higher in the vaginal delivery group than those in the CS group. An important discovery of our study was that fetal cord disulfide (-SS) level, which may reflect oxidative stress, was higher in newborns born via vaginal delivery when examined alone. However, in both maternal and fetal cord blood, the combined ratios, SS/SH ratio (%), SS/Total thiol ratio (%), and SH/Total thiol ratio (%) were observed to be similar between the groups in both maternal and fetal cord blood. It was observed that as the mother's weight gained during pregnancy increased, SS/SH and SS/total thiol increased (positive correlation), while SH/total thiol decreased (negative correlation).

CONCLUSIONS

Our results showed that the dynamic thiol-disulfide homeostasis was greatly influenced by the way of delivery and supported the idea that vaginally-delivered infants may have more oxidative stress.

Validation of assays for measurement of oxidant compounds in saliva of pigs: Thiobarbituric acid reactive substances (TBARS), carbonyl, and reactive oxygen species (ROS)

Thiobarbituric acid reactive substances (TBARS), carbonyls and reactive oxygen species (ROS) are oxidant compounds that can provide useful information on the oxidative status. Pigs can be affected by oxidative stress in different situations including physiological conditions such as lactation and also in different diseases, and the measurement of these three analytes in saliva could be potentially useful as biomarkers of the redox status in this species. Assays for the measurement of TBARS and carbonyls by spectrophotometry and ROS by luminol-based chemiluminescence in pigs' saliva were analytically validated and were applied in saliva of pigs after an in vitro incubation with different doses of ascorbic acid (AA). All the assays showed a satisfactory analytical precision and accuracy. The 240 h-incubation of saliva samples with 60 mM of AA induced to an increased TBARS and carbonyls production. TBARS, carbonyls and ROS can be estimated in saliva of pigs by the assays validated in this report. In addition, these assays can detect changes in the concentration of these analytes associated to incubation of saliva samples with AA.

Thiol-disulfide homeostasis in irritable bowel syndrome

OBJECTIVE

The etiopathogenesis and pathophysiological mechanism of irritable bowel syndrome (IBS) is not fully known. In this study, evaluating dynamic thiol-disulfide homeostasis (TDH) in patients with IBS was aimed.

SUBJECTS AND METHODS

A total of 92 people, 46 IBS patients and 46 healthy sex and aged-matched volunteers, were included in the study. Thiol/disulfide parameters in serum were measured in all cases, and the two groups were compared.

RESULTS

Disulfide levels (21.9 ± 5.0 µmol/L vs. 19.4 ± 4.2 µmol/L, respectively; p < 0.001), disulfide/native thiol (5.7%  ± 1.2% vs. 4.9% ± 0.8%, p < 0.001, respectively) and disulfide/total thiol ratio (5.1% ± 0.9% vs. 4.5% ± 0.7%, respectively, p < 0.001) were found to be higher in IBS patients, and native thiol/total thiol ratio (89.8% ± 1.9%, 90.6% ± 1.9%, p < 0.001, respectively) was found to be lower in IBS patients.

CONCLUSIONS

In our study, it was shown that TDH is impaired in IBS, which is an important result supporting studies showing that oxidative stress plays a role in IBS. On the other hand, it is thought that this study will contribute to the literature in terms of being the first study evaluating TDH in adult IBS.

The relationship between intraoperative body temperature and thiol/disulfide balance in geriatric patients undergoing elective transurethral prostate resection surgery with spinal anesthesia

OBJECTIVE

We aimed to investigate the relationship between intraoperative body temperature and thiol/disulfide balance in geriatric patients scheduled for elective transurethral prostate resection surgery with spinal anesthesia.

PATIENTS AND METHODS

71 patients classified as categories 1 and 2, according to American Society of Anesthesiologists (ASA) classification, were included in the study. The core temperature of the patients was recorded in the operating room after monitoring, at 5 and 30 minutes after spinal anesthesia. Total thiols, native thiols, disulfide amounts, disulfide/native thiol, disulfide/total thiol, and native thiol/total thiol were calculated as percentages after monitorization (Tpreoperative) and at 60 minutes after spinal anesthesia (Tintraoperative).

RESULTS

The disulfide levels in the Tintraoperative period (29±8.9 mmol/L) were higher than the disulfide levels measured in the Tpreoperative period (18.2±8.8 mmol/L) (p<0.001). In the Tpreoperative period, the disulfide/native thiol (%) level was 4.6±2, while the disulfide/total thiol (%) level was 4.2±1.6. In the Tintraoperative period, the disulfide/native thiol (%) level was 8±2.3, while the disulfide/total thiol (%) level was 6.8±1.7. Native thiol/total thiol (%) levels for the Tpreoperative and Tintraoperative periods were 91.5±3.3 mmol/L and 86.3±3.4 mmol/L, respectively. A correlation was found between native, total thiol levels and patient age in the Tpreoperative and Tintraoperative periods.

CONCLUSIONS

Oxidative stress can be reduced in geriatric patients with the possibility of developing involuntary perioperative hypothermia by regularly monitoring body temperature and applying warming techniques.

Evaluation of the effects of empagliflozin on acute lung injury in rat intestinal ischemia-reperfusion model

BACKGROUND

Empagliflozin is a selective sodium-glucose co-transporter (SGLT2) inhibitor that is approved for the treatment of type 2 diabetes. The beneficial effects of empagliflozin on other organ systems including the heart and kidneys have been proven. The aim of this study is to evaluate the role of empagliflozin on acute lung injury induced by intestinal ischemia-reperfusion (I/R).

MATERIALS AND METHODS

A total of 27 male Wistar albino rats were divided into three groups: sham, I/R, and I/R + empagliflozin; each group containing nine animals. Sham group rats underwent laparotomy without I/R injury. Rats in the I/R group underwent laparotomy, 1 h of after ischemia-reperfusion injury (superior mesenteric artery ligation was followed by 2 h of reperfusion). Rats in I/R were given empagliflozin (30 mg/kg) by gastric gavage for 7 days before the ischemia-reperfusion injury. All animals were killed at the end of reperfusion and lung tissue samples were obtained for immunohistochemical staining and histopathological investigation in all groups.

RESULTS

Serum glucose, AST, ALT, creatinine, native thiol, total thiol, and disulfide levels and disulfide-native thiol, disulfide-total thiol, and native thiol-total thiol ratios as well as the IMA levels were analyzed and compared among the groups. While intestinal I/R significantly increases serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), and creatinine levels; did not cause any change in homeostasis parameters and IMA level. Empagliflozin treatment had no significant effect on biochemical parameters. Empagliflozin treatment induced a significant decrease in positive immunostaining for IL-1, IL-6, TNF-alpha, caspase 3, caspase 8, and caspase 9 compared to the I/R group in lung tissue samples. Intestinal I/R caused severe histopathological injury including edema, hemorrhage, increased thickness of the alveolar wall, and infiltration of inflammatory cells into alveolar spaces. Empagliflozin treatment significantly attenuated the severity of intestinal I/R injury.

CONCLUSIONS

It was concluded that empagliflozin treatment may have beneficial effects in acute lung injury, and, therefore, has the potential for clinical use.

Effect of Remote Ischemic Preconditioning in Total Knee Arthroplasty on Thiol-Disulfi de Balance: a Randomized Controlled Study

PURPOSE OF THE STUDY The purpose of this study was to minimize tourniquet-induced ischemia-reperfusion injury (IRI) in total knee arthroplasty (TKA) surgery using the remote ischemic preconditioning (RIPC) model, as well as to assess antioxidant balance with thioldisulfi de homeostasis (TDH). The secondary goal is to evaluate the impact of RIPC on TKA clinical outcomes. MATERIAL AND METHODS Patients in the ASA I-III group who underwent elective TKA were enrolled in this prospective, randomized, double-blind clinical research. TDH parameters were measured individually in groups with (Group I) and without (Group K) RIPC at the following times: preoperative (T0), right before the pneumatic tourniquet was opened (T1), 1 (T2), 6 (T3), and 24 (T4) hours after it was opened. In addition, at 3-hour intervals, the postoperative pain level was assessed using a visual analog scale (VAS). RESULTS This study included 60 cases (Group K; n=30, Group I; n=30). Both groups had equal native thiol, total thiol, disulfi de levels, disulfi de/native thiol, disulfi de/total thiol, and native thiol/total thiol ratios (p>0.05 for each). The change in native thiol, total thiol, and disulfi de values at T0 and T4 periods, however, was not statistically signifi cant for Group K (p=0.049, p=0.047, p=0.037, and p=0.217, p=0.191, p=0.220, respectively). At the 15th hour, VAS values in group I were considerably lower than in Group K (p=0.002). DISCUSSION This prospective, randomized, controlled trial examined how RIPC affected tourniquet-induced IRI-induced oxidative stress in TKA surgery. Lower native, total, and disulfi de levels at each postoperative time point were signifi cant. RIPC may reduce tourniquet-induced IRI-induced oxidative stress and TDH in TKA surgery. RIPC also reduced postoperative discomfort. CONCLUSIONS Our fi ndings suggest that RIPC may protect against the oxidative stress caused by IRI during limb surgery with a tourniquet and improve postoperative clinical outcomes. Key words: remote ischemic preconditioning, ischemia-reperfusion injury, thiol-disulfi de balance, oxidative stress, total knee arthroplasty.

Diagnostic value of oxidative stress markers in patients presenting with primary dysmenorrhea to the emergency department

Background and Aim

Primary dysmenorrhea (PD) is a common presentation for emergency departments. This study investigates the diagnostic value of oxidative stress and ischemia markers in patients with PD.

Materials and Methods

The participants were classified into the PD group (patients with PD) and the control group (healthy volunteers). Thiol/Disulfide Homeostasis (TDH) parameters (Ds, Disulfide; NT, Native Thiol; TT, Total Thiol) and serum ischemia modified albumin (IMA) levels of the groups were measured. The Numeric Rating Scale (NRS) was used for pain assessment. Bivariate correlation analysis was performed to test the relationship between NRS and oxidative stress parameters. A P < 0.05 was considered significant.

Results

A total of 135 patients (PD group, n = 83; Control group, n = 52) were included in the study. PD group had statistically higher oxidant biomarkers (Ds level, Ds/NT ratio and Ds/TT ratio) and lower antioxidant biomarkers (NT/TT ratio) compared to the control group (p = 0.001; 0.003; 0.002, and 0.002, respectively). Serum IMA level in the PD group was higher than in the control group (P = 0.000). There was a positive correlation between IMA and NRS score (r = 0.342, P < 0.01), but no correlation was found between the other oxidative stress parameters and NRS.

Conclusions

PD is characterized by increased oxidative stress and ischemia in the endometrium, which can be detected by TDH parameters and serum IMA. NRS score in PD patients is positively correlated with serum IMA level, which suggests IMA level can be valuable to determine the severity of endometrial ischemia and pain in patients with PD.

Dynamic thiol/disulphide homeostasis and ischemic modified albumin levels in isolated oligohydramnios

OBJECTIVE

Oligohydramnios is defined as amniotic fluid index in ultrasonographic measurement is less than 5 percentile according to gestational age, the amniotic fluid volume is ≤ 5 cm, or if the single deepest dial is < 2 cm. The condition of oligohydramnios that not with fetal structural/chromosomal abnormalities, intrauterine growth retardation, intrauterine infection and maternal disease is described as isolated oligohydramnios (IO). The aim of this study is to examine whether oxidative stress and reactive oxygen species (ROS) have a place in the pathophysiology of IO.

MATERIALS AND METHODS

In this prospective case-control study, a total of 126 participants were included. The patient group consisted of 65 patients who were diagnosed IO, and the control group consisted of 61 healthy normal pregnants. Native thiol (-SH), total thiol (-SH + -SS), dynamic disulfide (-SS), IMA values from maternal serum were measured and compared between groups.

RESULTS

Maternal serum -SH and -SH + -SS values were significantly lower in the IO group than in the control group (409.47 ± 55.36 μmol/L vs. 437.40 ± 48.68 μmol/L, p = 0.03 and 457.40 ± 63.01 μmol/L vs. 484.59 ± 52.75 μmol/L, p = 0.01). In the IO group when -SS/-SH and -SS/-SH + -SS ratio was found to be statistically significantly higher than control group (5.84 ± 1.1 vs 5.41 ± 0.71, p = 0.01 and 5.2 ± 0.88 vs 4.8 ± 0.58, p = 0.01), -SH/-SH + -SS ratio was significantly lower (89.56 ± 1.7 vs 90.24 ± 1.16, p = 0.01). There was no significant difference in terms of -SS value (p = 0.66). IMA value was significantly higher in the IO group than control group (0.76 ± 0.10 ABSU vs 0.68 ± 0.06, p < 0.01). It is seen as a result of ROC analysis that -SH, -SH + -SS, -SS/-SH, -SS/-SH + -SS, -SH/-SH + -SS and IMA values have a diagnostic value for IO (p < 0.05).

CONCLUSION

The thiol/disulfide balance shifted towards oxidative stress in IO compared to control group. So oxidative stress and ROS have a place in the pathophysiology of IO.

Evaluation of thiol-disulfide homeostasis in pseudoexfoliation glaucoma and primary open-angle glaucoma

Aims

This study aimed to compare the serum thiol-disulfide homeostasis, total antioxidant status (TAS), and total oxidant status (TOS) in patients with pseudoexfoliation glaucoma (PEG) patients, primary open-angle glaucoma (POAG) patients, and healthy individuals (control).

Methods

Ninety subjects were included in this study. Three groups were separated as PEG, POAG, and control. All groups were chosen to be similar in terms of age and gender. Blood samples were obtained following an overnight fasting state and were collected on the ice at 4°C. The serum samples were separated from the cells by centrifugation at 3000 rpm for 15 min and were stored at -80°C. Serum samples analyzed for TAS and TOS, native thiol, total thiol, disulfide, and native thiol/disulfide ratio.

Results

TAS and TOS levels of PEG patients were 1.2892 ± 0.0905 mmol/L; 5.0191 ± 2.7722 μmol/L, respectively. TAS and TOS levels of POAG patients were 1.2741 ± 0.1252 mmol/L; 4.1674 ± 1.7723 μmol/L, respectively. TAS and TOS levels of the control group were 2.3414 ± 0.1409 mmol/L; 4.0931 ± 0.1107 μmol/L, respectively. The TAS level was significantly lower in PEG and POAG groups compared to control. TOS level showed no significant differ ¬ ence between PEG, POAG, and control groups (P > 0.05). The mean serum total thiol and native thiol levels were significantly lower in patients with PEG compared to POAG and control group; there was no significant difference between the POAG and control group (P > 0.05). The mean serum disulfide level was significantly lower in patients with PEG compared to POAG (P = 0.018).

Conclusion

Low levels of TAS were observed in patients with glaucoma, which was likely a response to the increased oxidative stress observed in these patients. While total thiol and native thiol levels were higher in the PEG group, the disulfide level was higher in the POAG group. TAS and TOS levels showed no significant difference between POAG and PEG groups.

Effects of smoking on thiol/disulfide homeostasis

OBJECTIVE

Cigarette smoking is an important risk factor for many diseases. This study aimed to evaluate whether cigarette smoking is associated with changes in the thiol/disulfide homeostasis (TDH), a novel biomarker of systemic oxidative stress.

PATIENTS AND METHODS

Eighty-four smokers and 86 non-smoking healthy volunteers were enrolled. Serum native thiol, disulfide and total thiol levels, disulfide/native thiol, disulfide/total thiol, and native thiol/total thiol ratios were analyzed using a new colorimetric method. Carbon monoxide (CO) levels were measured by a piCO smokerlyzer instrument.

RESULTS

The native, total, and native/total thiol levels of smoking patients were significantly lower (p<0.001 for each), and disulfide, disulfide/native thiol, and disulfide/total thiol levels were significantly higher in smokers than the healthy controls (p<0.001 for each). The CO levels of all study participants were negatively correlated with native thiol (r= -0.627, p<0.001), total thiol (r= -0.569, p<0.001), native thiol/total thiol (r= -0.515, p<0.001), and positively correlated with disulfide (r=0.398, p<0.001), disulfide/native thiol (r=0.515, p<0.001) and disulfide/total thiol (r=0.515, p<0.001) levels.

CONCLUSIONS

To our knowledge, this investigation is the first in the literature that investigated TDH in cigarette smokers. Our results show that cigarette smoking may lead to oxidative stress and TDH shifts through disulfide side compared to the healthy group. Further studies with larger sample size are needed to confirm our results for showing the changes in TDH to contribute to the clinical practice.

The relationship between severity of ulcerative colitis and thiol-disulphide homeostasis

OBJECTIVES

The aim of the study was to determine dynamic thiol-disulphide homeostasis in patients with ulcerative colitis, compare it with those of healthy control and to investigate the relationship between the severity of the disease and homeostasisMETHODS: A total of 78 patients and 58 healthy subjects were included in the study. Serum native thiol, total thiol and disulphide amounts were measured by using a novel automated method. Obtained results were compared and relationships were determined by correlation analysis.

RESULTS

Serum native thiol, total thiol, disulphide amounts and disulphide/native thiol percent ratio (index) were significantly lower (p = 0.003 for index ratio and p < 0.001 for other parameters) in patients with ulcerative colitis than in healthy controls. Native thiol, total thiol and disulphide amounts were significantly higher (p < 0.001) in patients with ulcerative colitis in remission than in patients with active ulcerative colitis and near to those of healthy control. There were significant negative correlations between the severity of the disease and thiol-disulphide homeostasis parameters (r = -0.55, p < 0.001 for native thiol; r = -0.64, p < 0.0001 for total thiol; r = -0.65, p < 0.001 for disulphide and r = -0.33, p = 0.011 for index).

CONCLUSION

The thiol-disulphide homeostasis was weakened in ulcerative colitis. Strong correlations between the activity of the disease and thiol-disulfide homeostasis indicate that homeostasis may play a role in the pathogenesis of the disease (Tab. 3, Fig. 3, Ref. 30).

Thiol-disulphide homoeostasis as an oxidative stress marker in men with varicocele

Oxidative stress is the most common factor leading to infertility in men with varicocele. Reactive oxygen species and other markers of oxidative stress are measured to predict the extent of oxidative stress. Thiol groups are important antioxidants and essential molecules protecting organism against the harmful effects of reactive oxygen species. Thiol-disulphide homoeostasis is a unique, easy and new method to demonstrate oxidative stress. The aim of this study was to determine thiol-disulphide homoeostasis as an oxidative stress marker in infertile men with varicocele. The hormonal profile and parameters of thiol-disulphide homoeostasis were studied in 46 infertile men with varicocele, 70 fertile men with varicocele and 37 fertile controls. Infertile men with varicocele had significantly higher disulphide concentrations and disulphide/native thiol, disulphide/total thiol and native/total thiol ratios than those of fertile men with varicocele and fertile controls. According to these results, the blood plasma of patients with varicocele contains excessive oxidative stress, even in men with normospermia, and therefore, thiol-disulphide homoeostasis may be useful as an oxidative stress marker in men with varicocele.

Thiol/disulfide homeostasis in postmenopausal osteoporosis

AIM

To evaluate the impact of postmenopausal osteoporosis on thiol/disulfide homeostasis.

MATERIALS AND METHODS

A total of 75 participants were divided into two groups: Group 1 (n = 40) was composed of healthy postmenopausal women, and group 2 (n = 35) was composed of women with postmenopausal osteoporosis. Clinical findings and thiol/disulfide homeostasis were compared between the two groups.

RESULTS

The disulfide/native thiol ratio was 8.6% ± 3.6 in group 1 and 12.7% ± 8.4 in group 2 (p = 0.04). The disulfide/native thiol percent ratio was significantly higher in group 2 after adjustment for the years since menopause and age (p < 0.05). The native thiol/total thiol percent ratio was 85.6% ± 4.8 in group 1 and 73.8% ± 24.9 in group 2 (p = 0.01). The native thiol/total thiol percent ratio was significantly lower in group 2 after adjustment for the years since menopause and age (p < 0.05).

CONCLUSION

Thiol/disulfide homeostasis shifted to the disulfide side independent of age and years since menopause in postmenopausal osteoporosis.

Thiol/disulphide homeostasis in Bell's palsy as a novel pathogenetic marker

OBJECTIVES

The aim of this study was to investigate the relationship between Bell's palsy and a novel oxidative stress parameter, thiol/disulphide homeostasis.

DESIGN

A prospective study evaluating oxidative stress in Bell's palsy.

SETTING

This research took place in the department of Otorhinolaryngology, Ataturk Training and Research Hospital.

PARTICIPANTS

Totally, 77 patients with Bell's palsy and 38 healthy controls were included in this study.

MAIN OUTCOME MEASURES

The blood levels of total and native thiol and disulphide activity were assessed, and their levels were compared in the patients and controls.

RESULTS

There were statistically significant differences between the patients and controls regarding thiol/disulphide parameters. The mean native thiol and total thiol were significantly lower and disulphide levels were higher in the Bell's palsy than controls. On binary logistic regression analysis, the created model showed 45.3% variation. The cut-off value was 18.95 for disulphides.

CONCLUSION

Native and total thiol levels were low in the Bell's palsy. This metabolic disturbance may have a role in the pathogenesis of Bell's palsy.

Comparison of thiol/disulphide homeostasis parameters in patients with COPD, asthma and ACOS

OBJECTIVE

Chronic obstructive pulmonary disease (COPD), asthma and asthma-COPD overlap syndrome (ACOS) are obstructive pulmonary disorders with different manifestations. Status of oxidation in tissues is important in obstructive pulmonary disorders. Smoking, acute exacerbations of COPD and asthma were associated with a marked imbalance in oxidant or antioxidant status due to increased oxidative stress in tissues and blood. Oxidative conditions may cause a reversible formation of mixed disulphides among protein thiol groups. The aim of this study was to compare parameters related with thiol/disulphide homeostasis in patients with COPD, asthma and ACOS.

PATIENTS AND METHODS

Patients (n= 135, 69 females, 66 males) who were referred with a diagnosis of COPD, asthma or ACOS were included in the study. Thiol/ disulphide homeostasis parameters in blood were analysed by a newly established method that measures the exact thiol/ disulphide status in the body.

RESULTS

The patients with COPD, asthma or ACOS were similar for demographic parameters other than age and number of cigarettes smoked. Measured thiol/disulphide homeostasis parameters were similar among these patient groups. When these biochemical measurements were adjusted for age and number of cigarettes by using regression analysis, similarity for thiol/disulphide homeostasis parameters among patient groups persisted.

CONCLUSIONS

To best of our knowledge, this is the first study to compare thiol/disulphide homeostasis parameters in COPD, asthma and ACOS patients. Similarity of thiol/disulphide homeostasis parameters among these patient groups supports the current view of Dutch hypothesis that COPD, asthma and ACOS share similar pathophysiological features but display different clinical manifestations.

Dynamic thiol-disulfide homeostasis in hyperemesis gravidarum

OBJECTIVE

To determine serum thiol-disulfide homeostasis in hyperemesis gravidarum.

STUDY DESIGN

Twenty-six pregnant women with hyperemesis gravidarum and 37 healthy pregnant women were included in the study. Native thiol, disulfide and total thiol concentrations were measured with a novel automated method.

RESULTS

Serum disulfide levels were 15.68±4.41 μmol l(-1) in the hyperemesis gravidarum group and 13.49±2.81 μmol l(-1) in the healthy group (P=0.031). Native thiol levels were 213.86±26.29 μmol l(-1) in the hyperemesis gravidarum group and 232.18±19.21 μmol l(-1) in healthy group (P=0.004), and total thiol levels were 245.23±28.58 μmol l(-1) in the hyperemesis gravidarum group and 259.17±19.94 μmol l(-1) in the healthy group (P=0.038).

CONCLUSION

Native and total thiol were deficient in the hyperemesis gravidarum group and this deficiency was correlated with the severity of the disease. The thiol-disulfide balance has shifted to the oxidative side. This metabolic disturbance may have a role in the pathogenesis of hyperemesis gravidarum.

Evaluation of systemic oxidant/antioxidant status and paraoxonase 1 enzyme activities in psoriatic patients treated by narrow band ultraviolet B phototherapy

OBJECTIVES

Ultraviolet B is a potent oxidative stress (OS) inducer in the skin; however, there are no data about the systemic oxidative effect of narrow band ultraviolet B (NB-UVB) phototherapy. In this study, we aimed to investigate the change in the OS status of psoriatic patients who were treated by NB-UVB phototherapy and to determine the relationships between OS, psoriasis severity, and systemic inflammatory condition.

METHODS

Twenty-four psoriatic patients were treated with a total of 30 sessions of NB-UVB irradiation. Psoriasis area and severity index (PASI), serum levels of high sensitive C-reactive protein (hsCRP), total antioxidant status (TAS), total oxidant status (TOS), the oxidative stress index (OSI), serum paraoxonase (PON), and arylesterase (ARE) activities before and after NB-UVB therapy were determined.

RESULTS

PASI scores significantly decreased after NB-UVB therapy (P = 0.001). The pre- and post-treatment hsCRP and TAS levels were similar (P = 0.253 and 0.301, respectively). TOS and OSI values significantly increased after phototherapy (both P < 0.001). PON and ARE activities did not change after treatment (both P > 0.05). There was no correlation between PASI and hsCRP, TAS, TOS, OSI, PON, and ARE values (P > 0.05).

CONCLUSION

A systemic OS may emerge in psoriatic patients treated by NB-UVB phototherapy.

The relationship between oxidative stress, smoking and the clinical severity of psoriasis

BACKGROUND

Recent studies suggested that increased oxidant products and decreased antioxidant system functions may be involved in the pathogenesis of psoriasis. In this study, we investigated total oxidative status, Paraoxonase (PON)1/arylesterase enzyme activities and severity of the disease in smoker and non-smoker psoriatic patients.

METHODS

Fifty-four patients with plaque type psoriasis (28 smokers and 26 non-smokers) and 62 healthy volunteers (16 smokers and 46 non-smokers) were enrolled in the study. Serum total oxidant status (TOS), total antioxidant capacity (TAC) and arylesterase levels were measured, and oxidative stress index (OSI) was calculated in all participants.

RESULTS

Psoriasis Area and Severity Index scores were significantly higher in smoker patients than in non-smoker patients (P = 0.014). Both smoker and non-smoker patients had significantly increased TOS levels and OSI values and decreased TAC levels than healthy subjects (all P values = 0.000). The TAC and TOS levels, OSI values and arylesterase activities were similar between smoker and non-smoker patients. The levels of triglyceride (TG), total cholesterol (TC), low-density lipoprotein (LDL) and high-density lipoprotein (HDL) were not significantly different between smoker and non-smoker psoriasis patients. When compared with non-smoking controls, only smoking psoriasis patients had significantly higher TG (P = 0.005), lower HDL (P = 0.022) and lower arylesterase levels (P = 0.015). There were no significant correlations with Psoriasis Area and Severity Index (PASI) scores and TAC, TOS, OSI, TG, TC, HDL and LDL levels in all psoriasis patients.

CONCLUSIONS

Oxidative stress is increased in psoriasis patients regardless of their smoking status. The decreased arylesterase activity in smoker psoriasis patients suggested that smoking may be a considerable risk factor that increases the severity of psoriasis by increasing oxidative stress in these patients.

Assessment of serum paraoxonase and arylesterase activities in early pregnancy failure

QUESTIONS UNDER STUDY

Paraoxonase-1 (PON1) is an HDL-bound enzyme system which plays a key role in the protection of LDL and HDL from oxidation by hydrolysing activated phospholipids and lipid peroxide products. Oxidative stress has been involved in the pathogenesis of many complications of human pregnancy, including early pregnancy failure (EPF), preeclampsia and preterm labour. The purpose of this study was to determine serum paraoxonase/arylesterase activities and lipid hydroperoxide (LOOH) levels as an oxidative stress indicator in women with EPF.

METHOD

Paraoxonase/arylesterase activities and LOOH levels were assessed in women with EPF (n = 40) and healthy continuum pregnant women without EPF (n = 38) before 12 weeks' gestation. Serum basal and salt-stimulated paraoxonase/arylesterase activities were measured spectrophotometrically. LOOH levels were measured by ferrous oxidation with a xylenol orange assay. Student's t-test and the Pearson correlation were used for statistical analysis.

RESULTS

We found that basal and salt-stimulated paraoxonase/arylesterase activities were significantly lower in women with EPF than in women without EPF (all p <0.05), while LOOH levels were significantly higher (p = 0.009).

CONCLUSION

Our study showed that decreased paraoxonase/arylesterase activities and increased LOOH levels may play a role in ethiopathogenesis through increased susceptibility to lipid peroxidation in women with EPF.

Oxidative Stress in BPH

INTRODUCTION

In the present study, we investigated the relationship between potency of oxidative stress and BPH and this may assist to contribute to the realistic explanation of the ethiopathogenesis of BPH.

METHODS

Seventy four newly diagnosed men with BPH (mean age: 54+/-11.2), who had not undergone any previous treatment for BPH, and 62 healthy volunteers (mean age: 55+/-14) were enrolled in the present study. To determine the antioxidative status of plasma, total antioxidant capacity (TAC) was calculated, and to determine the oxidative status of plasma (TOS) total peroxide levels were measured. The ratio of TAC to total peroxide was accepted as an indicator of oxidative stress (OSI). Data are presented as mean SD +/- unless specified. Student t-test and correlation analyses were used to evaluate the statistical significance differences in the median values recorded for all parameters between BPH and control group.

RESULTS

Plasma TAC TOS were found in patients and controls (1.70 +/- 0.32, 1.68 +/- 0.19 micromol Trolox Equiv./L), (12.48 +/- 1.98, 12.40 +/- 1.14 micromol / L) respectively. OSI was calculated as 7.57 +/- 1.91, 7.48 +/- 1.33, respectively. Plasma TAC, TOS and OSI levels were not found to be significantly difference between patients and control subjects (p>0.05, p>0.05, p>0.05).

CONCLUSIONS

The present study has shown that there were not relationship between potency of oxidative stress and BPH. Further well designed studies should be planned to find out whether the oxidative stress-related parameters play role in BPH as an interesting pathology in regard of the etiopathogenesis.

Oxidative Stress in BPH

INTRODUCTION:In the present study, we investigated the relationship between potency of oxidative stress and BPH and this may assist to contribute to the realistic explanation of the ethiopathogenesis of BPH.METHODS:Seventy four newly diagnosed men with BPH (mean age: 54+/-11.2), who had not undergone any previous treatment for BPH, and 62 healthy volunteers (mean age: 55+/-14) were enrolled in the present study. To determine the antioxidative status of plasma, total antioxidant capacity (TAC) was calculated, and to determine the oxidative status of plasma (TOS) total peroxide levels were measured. The ratio of TAC to total peroxide was accepted as an indicator of oxidative stress (OSI). Data are presented as mean SD +/- unless specified. Student t-test and correlation analyses were used to evaluate the statistical significance differences in the median values recorded for all parameters between BPH and control group.RESULTS:Plasma TAC TOS were found in patients and controls (1.70 +/- 0.32, 1.68 +/- 0.19 micromol Trolox Equiv./L), (12.48 +/- 1.98, 12.40 +/- 1.14 micromol / L) respectively. OSI was calculated as 7.57 +/- 1.91, 7.48 +/- 1.33, respectively. Plasma TAC, TOS and OSI levels were not found to be significantly difference between patients and control subjects (p>0.05, p>0.05, p>0.05).CONCLUSIONS:The present study has shown that there were not relationship between potency of oxidative stress and BPH. Further well designed studies should be planned to find out whether the oxidative stress-related parameters play role in BPH as an interesting pathology in regard of the etiopathogenesis.Keywords: benign prostatic hyperplasia, oxidative stress, prostate

Assessment of serum paraoxonase and arylesterase activity in patients with endometrial cancer

PURPOSE OF INVESTIGATION

Serum paraoxonase (PON 1) is one of the most important enzymatic antioxidants that hydrolyzes lipid peroxidation, an indicator of carcinogenic activity. The aim of this study was to compare the serum levels of paraoxonase and arylesterase activity in patients with endometrial cancer to those of healthy controls.

METHODS

Serum paraoxonase and arylesterase activities, total free sulphydryl (-SH) groups and lipid hydroperoxide (LOOH) levels were measured in patients with endometrial cancer (n = 20) and controls (n = 23).

RESULTS

Serum paraoxonase, arylesterase activities and total -SH group levels were significantly lower in patients compared to controls (p < 0.05, p < 0.05 and p < 0.001; respectively), while LOOH levels were significantly higher (p < 0.001). Among patients, serum paraoxonase and arylesterase activities were inversely correlated with LOOH levels (r = -0.680, p < 0.05; r = -0.708, p < 0.001; respectively), while these were positively correlated with the total -SH group (r = 0.526, p < 0.05; r = 0.508, p < 0.05; respectively).

CONCLUSION

Reduced serum PON 1 activity might contribute to an impaired antioxidant defense system which plays a critical role in carcinogenesis in patients with endometrial cancer.

Serum paraoxonase and arylesterase activities for the evaluation of patients with chronic hepatitis

The sensitivity of standard biochemical tests for liver function is low and insufficient for a reliable determination of the presence or absence of liver disease. The aim of the present study was to investigate serum paraoxonase and arylesterase activities and lipid hydroperoxide (LOOH) levels, and to find out that whether the measurement of serum paraoxonase and arylesterase activities would be useful as an index of liver function status in chronic hepatitis (CH). Fourty-four patients with CH (24 CHB and 20 CHC) and 38 controls were enrolled. Serum paraoxonase and arylesterase activities were detected spectrophotometrically. LOOH levels were measured by the FOX-2 assay. Serum paraoxonase and arylesterase activities were significantly lower in patients with CH than controls (p < 0.001 for both), while LOOH levels were significantly higher (p < 0.001). Paraoxonase and arylesterase activities were inversely correlated with LOOH levels (r = -0.394, p < 0.05; r =-0.362, p < 0.05, respectively). Fibrosis scores of CH patients were significantly correlated with paraoxonase and arylesterase activities and LOOH levels (r =-0.276, p < 0.05; r = -0.583, p < 0.001 and r = 0.562, p < 0.001, respectively). Our results indicated that decrease in the activities paraoxonase and arylesterase may play a role in the pathogenesis of CH. In addition, serum paraoxonase and arylesterase activities measurement may add a significant contribution to the liver function tests.

Paraoxonase and arylesterase activities in coronary artery disease

BACKGROUND

Paraoxonase-1 is an enzyme with three activities which are inversely related to cardiovascular diseases. Accordingly, the aim of the study was to investigate the paraoxonase, arylesterase activities and oxidative/anti-oxidative status in coronary artery disease (CAD) and their correlation with the extent of CAD.

MATERIALS AND METHODS

Study populations of 193 patients with angiographically documented CAD, 83 patients with normal coronary angiograms (NCAD) and 55 healthy volunteers were included in the study. The patients with CAD were divided into three categories according to the number of diseased coronaries. Also, a Gensini score was calculated for each patient. Serum paraoxonase and arylesterase activities were measured spectrophotometrically. Oxidative and anti-oxidative status was evaluated by measuring serum lipid hydroperoxide (LOOH), total anti-oxidant status (TAS) and free sulfhydryl groups (-SH = total thiol). Lipid parameters were determined by routine laboratory methods.

RESULTS

Serum paraoxonase and arylesterase activities, TAS and -SH levels were lower in the CAD group compared with the NCAD group and control group (P < 0.05, all). Serum LOOH levels of the CAD group were greater than those in both the control and NCAD groups (P < 0.05). The major decreases in paraoxonase, arylesterase activities, -SH and TAS levels and the major increase in LOOH levels were observed in the 3-vessels disease group. In multiple linear regression analysis, the Gensini score was independently correlated with paraoxonase activity (beta = -0.469, P < 0.001), -SH levels (beta = -0.232, P < 0.001), HDL levels and history of diabetes.

CONCLUSIONS

Both paraoxonase activity and -SH levels are independently associated with the presence and extent of CAD. Reduced paraoxonase activity and -SH levels may play a role in the severity of coronary atherosclerosis.

Total antioxidant capacity in children with acute appendicitis

AIM

This study aimed to investigate antioxidant capacity by using a novel automated method in children with acute appendicitis.

METHODS

Blood samples were obtained from consecutive patients with acute appendicitis (appendicitis group, n = 12) and acute abdominal pain due to non surgical disease (non-appendicitis group, n = 11), and from patients with inguinal hernia (healthy group, n = 12) as the control group. At admission, total antioxidant capacity (TAC) levels of plasma were evaluated in all patients by a method recently developed by Erel. Four other major individual plasma antioxidant components, the levels of total protein, albumin, uric acid and bilirubin, were also evaluated. Total antioxidant capacity in patients with acute appendicitis was statistically compared with the two other groups.

RESULTS

While the TAC level in the appendicitis group was significantly greater than in the non-appendicitis group, no significant difference was found in healthy groups (p < 0.05, p > 0.05, 1.94 +/- 0.38, 1.40 +/- 0.36, and 1.99 +/- 0.35 respectively). Individual components of total antioxidant capacity, i.e. total protein, albumin, uric acid and bilirubin concentrations, were also higher in the patients with acute appendicitis than those of the other two control groups.

CONCLUSIONS

Our data show that children with acute appendicitis do not have deficient blood plasma antioxidant capacity. These results provide evidence that acute appendicitis results in more induction of antioxidative response than non-surgical diseases.

Comparison of oxidative/antioxidative status of penile corpus cavernosum blood and peripheral venous blood

The aim of the study is to determine and to compare the oxidative and antioxidative status of penile corpus cavernosum and peripheral venous blood. A total of 28 adult healthy males were included in the study. Whole blood was simultaneously withdrawn from penile corpus cavernosum and the cubital vein and their plasma separated. Total antioxidant capacity (TAC), vitamin C, total protein, albumin, uric acid, bilirubin and total peroxide (TP) levels of both plasma samples were measured and compared. While TAC, total protein, albumin, bilirubin and uric acid levels were higher, vitamin C levels were lower in cavernosal blood than that of peripheral blood. On the other hand, TP level was found to be higher in penile blood samples than that of peripheral blood. We thought that the normal erectile process of the penile cavernosal body leads to increased production of oxidants as in the mechanism of ischaemia-reperfusion; however, the increase of TAC can prevent development of oxidative injury.

Effects of tobacco smoking on plasma selenium, zinc, copper and iron concentrations and related antioxidative enzyme activities

OBJECTIVES

The aim of the study was to investigate whether alterations in antioxidative enzyme activities are dependent on their cofactor concentrations in tobacco smokers.

DESIGN AND METHODS

Plasma selenium, copper, zinc and iron concentrations, and the activities of related erythrocyte antioxidative enzymes copper-zinc superoxide dismutase (Cu-Zn SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) were measured in tobacco smokers and compared with those of nonsmokers. Plasma thiocyanate levels were measured as an index of smoking status.

RESULTS

While plasma copper concentration and erythrocyte Cu-Zn SOD activity were significantly higher, plasma selenium concentration and erythrocyte GSH-Px activities were significantly lower in tobacco smokers than in nonsmokers. There was no significant difference in plasma iron and zinc concentrations or erythrocyte CAT activity between the two groups. There were significant positive correlations between erythrocyte GSH-Px and plasma selenium levels, between Cu-Zn SOD and copper levels, and between CAT and iron levels, and a negative correlation between plasma thiocyanate and selenium content in tobacco smokers.

CONCLUSIONS

These findings suggest that antioxidative enzyme activities change depending on their cofactor concentrations in tobacco smokers.

Diagnostic performance characteristics of rapid dipstick test for Plasmodium vivax malaria

We compared the diagnostic performance characteristics of newly developed method, the rapid dipstick test, which provides colorimetric determination by developing antibody to the lactate dehydrogenase enzyme of parasites, with conventional standard thick-blood film examination. For the rapid test, OptiMAL commercial kits were used. The results were also evaluated with clinical findings from patients. The parasites were determined by microscopic examination of thick-blood films from 81 patients with vivax malaria from southeastern Anatolia, Turkey. The OptiMAL test results were found to be negative in five patients who were diagnosed clinically and through thick-film testing as having vivax malaria. There was no false positivity observed with the OptiMAL test. We concluded that this rapid malaria test has a lower level of sensitivity than the classical thick-blood-film test for malaria, but that these methods have equal specificity.

Oxidative stress of platelets and thrombocytopenia in patients with vivax malaria

Oxidative stress and antioxidative capacity of platelets and the relationship with thrombocytopenia were determined in patients with vivax malaria and compared with those of healthy subjects. Whole blood thrombocyte count, platelet superoxide dismutase and glutathione peroxidase activities of patients with vivax malaria were lower and platelet lipid peroxidation levels were higher in patients than those of healthy subjects. There was an important negative correlation between whole blood thrombocyte count and platelet lipid peroxidation level. The antioxidative mechanisms of thrombocytes were insufficient in malaria patients and caused oxidative stress. The oxidative damage of thrombocytes might be important in the ethiopathogenesis of thrombocytopenia occurring in malaria.

Maternal versus nonmaternal care and seven domains of children's development

A series of meta-analyses was conducted on findings from 59 studies to examine the linkage between maternal versus nonmaternal care, 7 indices of child behavior, and 10 potential moderators. Results indicate that children receiving nonmaternal care do not differ from children receiving maternal care on any of the 7 indices. Year of publication and psychometrics of outcome index were found to moderate the linkage between maternal versus nonmaternal care and attachment classification and between maternal versus nonmaternal care and child adjustment, respectively. Examination of the simultaneous impact of extent of care and age of entry on attachment behaviors revealed the moderating impact of the latter. Although it cannot be concluded that nonmaternal care has no impact on children, most of the analyses suggest that in and of itself, or in interaction with one factor at a time, nonmaternal care does not affect child development.

The frequency and etiology of anemia among children 6-16 years of age in the southeast region of Turkey

The frequency and etiology of anemia were investigated in 2,913 children between six and 16 years of age in Sanliurfa, in the southeast region of Turkey. Anemia was found in 142 (7.8%) children in the 6-11 years of age group, and in 16 (1.5%) in the 12-16 years of age group; in total, in 158 (5.4%) children. Causes were iron deficiency in 93 (58.9%) children, beta-thalassemia heterozygosity in 10 (6.3%) children, chronic disease that causes anemia of inflammation in 30 (19.0%) children, and intestinal parasitic infections in 17 (10.8%) children. In eight (5.1%) children, the cause of anemia could not be determined. The study's results showed that iron deficiency anemia and chronic and parasitic disease are important problems in schoolchildren of Sanliurfa, while beta-thalassemia and hemoglobinopathies have less importance.

Efficacy of cryotherapy and intralesional pentostam in treatment of cutaneous leishmaniasis

Forty-two CL patients with 60 lesions were treated with cryotherapy using liquid nitrogen twice for two months. Another group of fifty-five CL patients. With 73 lesions were treated with intralesional pentostam with pentostam, 67 of 73 lesions (92%) and with cryotherapy 47 of 60 lesions (78%) healed or markedly improved at the end of three months follow-up. This study shows that intralesional pentostam injection was effective than cryotherapy. However, both lines of treatment were well tolerated by the patients. They showed no severe side effects and no significant changes in laboratory values. It is suggested that cryotherapy is an alternative to intralesional pentostam injection.

Adenosine deaminase and guanosine deaminase activities in sera of patients with viral hepatitis

In order to investigate purin and primidin metabolism pathways in hepatitis, adenosine deaminase (ADA) and guanosine deaminase (GDA) activities in sera of patients with different types and manifestations of viral hepatitis disease (A, B, C, D, E, chronic, acute) were investigated and compared with the control group of healthy individuals. Hepatitis cases were classified with respect to their serological findings and clinics. When compared all the hepatitis cases with the controls, levels of aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase enzymes, as well as ADA and GDA, were significantly higher than the control group (p<0.01). Levels of ADA and GDA in hepatitis cases were determined as 26.07 11.98 IU/l and 2.37 1.91 IU/l, respectively. When compared their ADA and GDA levels amongst the classified hepatitis groups, there was no difference in ADA levels amongst cases (p>0.05). However, GDA levels in hepatitis A group were closed to the controls. Increase in serum ADA activities in hepatitis forms may be dependent on and reflect the increase in phagocytic activity of macrophages and maturation of T-lymphocytes, and may be valuable in monitoring in viral hepatitis cases.

Role of lipids, lipoproteins and lipid peroxidation in thrombocytopenia in patients with vivax malaria

Possible roles of oxidative and metabolic changes of lipids in the development of thrombocytopenia in patients with vivax malaria were investigated. Serum total cholesterol, HDL and LDL cholesterols, triglycerides, lipid peroxidation level and platelet counts were determined in 60 patients with vivax malaria and compared with 50 healthy individuals. Inter-relationships of parameters were investigated. In patients, serum total cholesterol, HDL and LDL cholesterol concentrations and platelet counts were lower, and serum triglycerides and plasma lipid peroxidation concentrations were higher than those of control subjects. Significant relationships were found among serum lipid parameters, plasma lipid peroxidation and thrombocyte counts. Decrease in total cholesterol, HDL and LDL cholesterols and platelet counts may be related or secondary to oxidative stress. In the treatment of thrombocytopenia required in the some cases of malaria, the supplementation of antioxidative vitamins may be considered.

Reactive nitrogen and oxygen intermediates in patients with cutaneous leishmaniasis

The metabolisms of reactive nitrogen and oxygen intermediates (RNI and ROI) in patients with cutaneous leishmaniasis (CL) were investigated and compared with those of healthy subjects. To determine RNI metabolism, nitrite plus nitrate concentrations were measured spectrophotometrically. Nitrite concentration in plasma was determined directly by the Griess method. Nitrate levels in plasma were measured after reduction into nitrite by using copper-cadmium-zinc. ROI metabolism was evaluated by measuring erythrocyte superoxide dismutase, catalase and glutathione peroxidase activities. Plasma nitrite plus nitrate levels and erythrocyte superoxide dismutase activity were higher in the patient group than healthy subjects (p<0.01). In contrast, erythrocyte catalase and glutathione peroxidase activities were lower (p<0.05, p<0.01, respectively). ROI metabolism was altered in relation to hydrogen peroxide elevation in patients with CL. These alterations in ROI enable nitric oxide (NO) to amplify its leishmanicidal effect. The determination of ROI and RNI in patients with CL may be a useful tool to evaluate effector mechanisms of NO and clinical manifestations.

Alterations of serum selenium, zinc, copper, and iron concentrations and some related antioxidant enzyme activities in patients with cutaneous leishmaniasis

The aim of this study was to measure the alterations in serum selenium (Se), copper (Cu), zinc (Zn), and iron (Fe) concentrations and their carrier proteins, ceruloplasmin (Cp), transferrin (Tf) albumin, and related antioxidant enzyme activities, erythrocyte Cu-Zn superoxide dismutase (Cu-Zn SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) activities in patients with cutaneous leishmaniasis (CL). Erythrocyte Cu-Zn SOD activities, serum Cu concentrations, and Cp levels were found to be significantly higher in the patients group than those of controls. However, GSH-Px and CAT activities and Se, Zn, Fe, and Tf levels were lower in patients than in the control subjects. There were positive important correlation's between Cu-Zn SOD and Cp, Cu-Zn SOD and Cu, Cp and Cu, GSH-Px and Se, and Fe and CAT in the patients group. Our results showed that serum essential trace elements Se, Zn, Cu, and Fe concentrations and their related enzymes Cu-Zn SOD, GSH-Px, and CAT activities change in CL patients. The changes may be a part of defense strategies of organism and are induced by the hormonelike substances.

Meta-analyses comparing theory of mind abilities of individuals with autism, individuals with mental retardation, and normally developing individuals

A deficit in theory of mind (ToM) abilities has been described as the core deficit in autism. The authors performed 3 meta-analyses, comparing ToM abilities of individuals with autism, individuals with mental retardation (MR), and normally developing individuals. Results indicated that individuals with autism and MR have impaired ToM abilities. The etiology associated with MR (i.e., Down syndrome, undifferentiated etiology) was found to be an important moderator variable. Chronological age (CA) and verbal mental age (VMA) of the normally developing children and CA, VMA, and performance mental age of individuals with MR, and type of matching between the groups were also found to be moderator variables. Discussion focuses on the implication of the findings and emphasizes the need to consider the specific etiology of comparison groups when studying abilities and impairments of individuals with autism and MR.

Automated measurement of serum ferroxidase activity

A method is described for automated measurement of serum ceruloplasmin ferroxidase activity. In this method, Fe2+ ions are used as the substrate. In addition, a new calibration system without ceruloplasmin is also presented. Optimum assay reaction conditions were determined. Maximal catalytic activity was obtained at 0.45 mol/L acetate buffer, pH 5.8. The reagents and calibrator are stable for at least 6 months. Significant correlations between serum ferroxidase and p-phenylenediamine oxidase activities (r = 0.96; P <0.0001) and copper concentration (r = 0.93; P <0.0001) were found. The range for serum ceruloplasmin ferroxidase activity in healthy persons was 198-1107 U/L, and in patients with bronchial asthma it was 601-1912 U/L.