Thrombocytopenia in malaria: who cares?

Despite not being a criterion for severe malaria, thrombocytopenia is one of the most common complications of both Plasmodium vivax and Plasmodium falciparum malaria. In a systematic review of the literature, platelet counts under 150,000/mm3 ranged from 24-94% in patients with acute malaria and this frequency was not different between the two major species that affected humans. Minor bleeding is mentioned in case reports of patients with P. vivax infection and may be explained by medullary compensation with the release of mega platelets in the peripheral circulation by megakaryocytes, thus maintaining a good primary haemostasis. The speculated mechanisms leading to thrombocytopenia are: coagulation disturbances, splenomegaly, bone marrow alterations, antibody-mediated platelet destruction, oxidative stress and the role of platelets as cofactors in triggering severe malaria. Data from experimental models are presented and, despite not being rare, there is no clear recommendation on the adequate management of this haematological complication. In most cases, a conservative approach is adopted and platelet counts usually revert to normal ranges a few days after efficacious antimalarial treatment. More studies are needed to specifically clarify if thrombocytopenia is the cause or consequence of the clinical disease spectrum.     

Characterization of a more electronegatively charged LDL subfraction by ion exchange HPLC

Low density lipoproteins (LDL), collected from 32 normal male subjects (aged 30-60), were subfractionated by high resolution ion exchange chromatography (IE-HPLC). By this procedure two LDL subfractions were eluted. The first corresponds to normal LDL (nLDL); while the second one corresponds to a more electronegative subfraction, called LDL-. The mean percentage contribution of LDL- to native plasma LDL was of 3.9% (range 0.5-9.8%). The percentage concentration of LDL- in total native LDL did not correlate with plasma total cholesterol, triglycerides, and LDL cholesterol, whereas a significant negative correlation with high density lipoprotein cholesterol was found (r = -.38; p less than .05). LDL- was negatively correlated with LDL phospholipids (r = -.59; p less than .001), and with the LDL vitamin E content (r = -.63; p less than .001), and positively correlated with LDL proteins (r = -.35; p less than .05) and the content of thiobarbituric acid reactive substances (TBARS) in total LDL (r = .43; p less than .05). The TBARS molar content of LDL- was three times higher than in nLDL, with a mean concentration in LDL- of 7.3 mol/mol lipoprotein. By preparative IE-HPLC significant differences of the LDL- chemical composition were observed. The percentage content of cholesterol esters and of phospholipids was decreased, whereas proteins and free cholesterol were increased. Analysis by sodium dodecyl sulphate polyacrylamide gel electrophoresis revealed that besides apolipoprotein B-100 there was evidence of peptides with a higher molecular weight in LDL-.(ABSTRACT TRUNCATED AT 250 WORDS)     

The association between oxidative stress and obstructive lung impairment in patients with COPD

An oxidant/antioxidant imbalance is thought to play an important role in the pathogenesis of chronic obstructive pulmonary disease (COPD). We hypothesized that antioxidant capacity reflected by erythrocyte glutathione peroxidase (GPx), superoxide dismutase (SOD) and catalase (CAT) activities, and serum levels of the lipid peroxidation product malondialdehyde (MDA), may be related to the severity of obstructive lung impairment in patients with COPD. Erythrocyte GPx, SOD and CAT activities, and serum levels of MDA were measured in 79 consecutive patients with stable COPD. Pulmonary functional tests were assessed by body plethysmography. Moderate COPD (FEV1 50-80%) was present in 23, and severe COPD (FEV1 < 50%) in 56 patients. Erythrocyte GPx activity was significantly lower, and serum MDA levels were significantly higher in patients with severe COPD compared to patients with moderate COPD (GPx: 43.1+/-1.5 vs. 47.7+/-2.9 U/gHb, p<0.05, MDA: 2.4+/-0.1 vs. 2.1+/-0.1 nmol/ml, p<0.05). Linear regression analysis revealed a significant direct relationship between FEV1 and erythrocyte GPx activity (r = 0.234, p<0.05), and a significant inverse relationship between FEV1 and serum MDA levels (r = -0.239, p<0.05). However, no differences were observed in the erythrocyte SOD and CAT activities between the two groups of patients with different severity of COPD. Findings of the present study suggest that antioxidant capacity reflected by erythrocyte GPx activity and serum levels of the lipid peroxidation product MDA are linked to the severity of COPD.     

Mechanisms of Thrombocytopenia in Malignant Tertian Malaria

The mechanism of thrombocytopenia in six patients with falciparum malaria has been studied. All the patients recovered after antimalarial therapy, and cerebral malaria was not a feature. Radioactive-labelled platelets and fibrinogen were injected into the patients during the phase of thrombocytopenia. In all cases recovery of injected platelets was notably subnormal, indicating excessive splenic pooling of platelets. Platelet life span was moderately shortened in all patients, and platelet turnover increased approximately two-fold. Fibrinogen catabolism was moderately increased in all patients, but coagulation tests failed to reveal evidence of disseminated intravascular coagulation. The results suggest that in uncomplicated cases of malaria thrombocytopenia is the result of splenic pooling of platelets aggravated by a moderate decrease in platelet life span. In such cases thrombocytopenia is thus not the result of disseminated intravascular coagulation (D.I.C.), and heparin therapy is not indicated unless there is unequivocal ancillary evidence of D.I.C.     

A method to visualize the uncertainty of the prediction of radiobiological models

A method for quantitative visualization of the uncertainty in the predicted tumor control probability (TCP) and normal tissue complication probability (NTCP) in radiotherapy has been developed. Uncertainties of TCP and NTCP due to inter-individual variation of the underlying radiosensitivity parameters was simulated by sampling the prescribed dose from a uniform distribution and the radiosensitivity-parameters from a Gaussian distribution. The result is visualized as a scatter-plot superimposed to the population-based dose response curves using the prescribed dose as the common dosimetric variable. In addition, probability histograms are derived quantifying the probability of specific TCP- or NTCP-values for individual patients from the underlying population. The method is exemplified with a pleural mesothelioma case with the lung as organ at risk. A prescribed dose of 54 Gy together with radiosensitivity variations of 6% (tumor) and 10% (normal tissue) results in a TCP of 85% (range 68–94%, 90% confidence interval, CI) and an NTCP of 4% (range 3–6%, 90% CI), respectively. Increasing the radiosensitivity variation of the tumor to 15% and reducing the lung tolerance dose by 25% results in values of 84% (range 51–97%, 90% CI) for TCP and 9% (range 6–12%, 90% CI) for NTCP. Increasing the dose to 60 Gy leads to TCP- and NTCP-values of 93% (range 69–100%, 90% CI) and 12% (range 8–17%, 90% CI), respectively. The new method visualizes the uncertainty of TCP- and NTCP-values and hence of the therapeutic window. This can help the clinician to assess the treatment plan for the individual patient.     

Effect of retinoic acid on adenosine diphosphate and collagen-induced alterations in enzymes of GSH-linked antioxidant defence system of human blood platelets in vitro

Collagen stimulation of blood platelets resulted in significant increases in malondialdehyde (MDA) formation and activity of glucose-6-phosphate dehydrogenase (G6PDH) and a decrease in catalase and glutathione peroxidase (GPx). Retinoic acid (RA) pretreatment did not show any appreciable changes except for a decrease in G6PDH activity as compared with collagen alone. RA pretreatment of human blood platelets resulted in an increase in the activities of catalase and GPx, two important radical scavenging enzymes, with significant decrease in MDA formation when compared with ADP alone. It is suggested that RA has a significant effect on the antioxidant defence system in ADP stimulated platelets but not in the collagen stimulated platelets.     

Biological optimization of simultaneous boost on intra-prostatic lesions (DILs): Sensitivity to TCP parameters

The aim of this investigation was to explore the potential of biological optimization in the case of simultaneous integrated boost on intra-prostatic dominant lesions (DIL) and evaluating the impact of TCP parameters uncertainty.Different combination of TCP parameters (TD50 and γ50 in the Poisson-like model), were considered for DILs and the prostate outside DILs (CTV) for 7 intermediate/high-risk prostate patients. The aim was to maximize TCP while constraining NTCPs below 5% for all organs at risk. TCP values were highly depending on the parameters used and ranged between 38.4% and 99.9%; the optimized median physical doses were in the range 94–116 Gy and 69–77 Gy for DIL and CTV respectively. TCP values were correlated with the overlap PTV-rectum and the minimum distance between rectum and DIL. In conclusion, biological optimization for selective dose escalation is feasible and suggests prescribed dose around 90–120 Gy to the DILs. The obtained result is critically depending on the assumptions concerning the higher radioresistence in the DILs. In case of very resistant clonogens into the DIL, it may be difficult to maximize TCP to acceptable levels without violating NTCP constraints.     

Possible salivary and serum biomarkers for oral lichen planus

There are few reports concerning the potential for clinical application of oxidative stress (OS) and collagen degradation markers in oral lichen planus (OLP) patients. We investigated the possibility of using some disease-related biomarkers in saliva and serum of OLP patients. Our study included 30 patients with OLP and 30 controls. We evaluated serum and salivary OS biomarkers including 8-OHdG, MDA, uric acid, TAC and GPx. We also investigated collagen degradation markers such as CTX I and MMP-8. We found significantly increased salivary levels of MMP-8 and CTX I in the OLP group compared to controls and significant differences between the OLP and control groups in serum and saliva for 8-OHdG, MDA (significantly increased), uric acid, TAC and GPx (significantly reduced). Currently there are no criteria for evaluating which OLP patients have a greater risk of malignant transformation. In addition to clinical surveillance, the serum and salivary biomarkers that we evaluated may be useful biomarkers for monitoring OLP patients in the future.     

Severe disease in children hospitalized with a diagnosis of Plasmodium vivax in south-eastern Pakistan

ABSTRACT: BACKGROUND: Infection by Plasmodium vivax has been considered rarely threatening to life, but recent studies challenge this notion. This study documented the frequency and character of severe illness in paediatric patients admitted to a hospital in south-eastern Pakistan with a laboratory-confirmed diagnosis of vivax malaria. METHODS: An observational study of all 180 paediatric patients admitted with any diagnosis of malaria during 2010 was conducted: 128 P. vivax; 48 Plasmodium falciparum; and four mixed infections of these species. Patients were classified as having severe illness with any of the following indicators: Glascow coma scale <11; >2 convulsions; haemoglobin <5g/dL; thrombocytes <50,000/mL; blood glucose <45mg%; >70 breaths/min; or intravenous antimalarial therapy. Additionally, 64 patients with a diagnosis of vivax malaria were treated during 2009, and the 21 of these having severe illness were included in analyses of the frequency and character of severe illness with that diagnosis. RESULTS: During 2010, 39 (31%) or 37 (77%) patients with a diagnosis of P. vivax or P. falciparum were classified as having severe disease. Including the 2009 records of 64 patients having vivax malaria, a total of 60 (31%) patients with severe illness and a diagnosis of P. vivax were available. Altered mental status (Glascow coma scale score <11; or >2 convulsions) dominated at 54% of the 83 indicators of severe illness manifest among the patients with vivax malaria, as was true among the 37 children with a diagnosis of falciparum malaria and being severely ill; 58% of the 72 indicators of severe disease documented among them. No statistically significant difference appeared in frequencies of any other severe disease indicators between patients diagnosed with vivax or falciparum malaria. Despite such similarities, a diagnosis of falciparum malaria nonetheless came with 3.8-fold (95% CI = 1.8- 8.1) higher risk of presenting with severe illness, and 8.0-fold (95% CI = 2.1-31) greater likelihood of presenting with three or more severe disease indicators. Two patients did not survive hospitalization, one each with a diagnosis of falciparum or vivax malaria. CONCLUSIONS: Vivax malaria caused a substantial burden of potentially life-threatening morbidity on a paediatric ward in a hospital in south-eastern Pakistan.     

Influence of age on activities of antioxidant enzymes and lipid peroxidation products in erythrocytes and neutrophils of Down syndrome patients

Thirty-seven individuals with Down syndrome (DS) were divided into four age categories: (i) 1 to < 6 years, (ii) 6 to < 13 years, (iii) 13 to < 20 years, and (iv) over 20 years. Activities of antioxidant enzymes found in individual age categories were different, but the differences between age groups were not statistically significant. We confirmed significantly higher activities of Cu/Zn superoxide dismutase (SOD) and glutathione peroxidase (GPx) in blood cells of people with DS as compared to 35 controls, which consisted, for the first time, of siblings of children with DS. No significant differences were found in activities of catalase and glutathione reductase in DS vs. controls. A significant difference was observed in serum concentration of malondialdehyde (MDA) in DS vs. controls (8.39 +/- 0.34 micromol/l vs. 7.34 +/- 0.27 micromol/l; p = .021) and concentration of MDA in erythrocytes of individuals with DS between the third and fourth age group (p = .05). In DS persons, an elevated ratio of SOD to catalase plus GPx with respect to the controls in all age categories was found, suggesting oxidative imbalance, potentially contributing to accelerated aging observed in these persons.     

Two-dimensional imaging of tumour control probabilities and normal tissue complication probabilities

Aim

To create a presentation method of TCP and NTCP distributions calculated based on dose distribution for a selected CT slice.

Materials and methods

Three 24-bit colour maps – of dose distribution, delineated structures and CT information – were converted into m-by-n-by-3 data arrays, containing intensities of red, green, and blue colour components for each pixel. All calculations were performed with Matlab v.6.5. The transformation function, which consists of five linear functions, was prepared to translate the colour map into a one-dimensional data array of dose values. A menu-driven application based on the transformation function and mathematical models of complication risk (NTCP) and treatment control probability (TCP) was designed to allow pixel-by-pixel translation of colour maps into one-dimensional arrays of TCP and NTCP values.

Results

The result of this work is an application created to visualize the TCP and NTCP distribution for a single CT scan based on the spatial dose distribution calculated in the treatment planning system. The application allows 10 targets (PTV) and 10 organs at risks (OaR) to be defined. The interface allows alpha/beta values to be inserted for each delineated structure. The application computes TCP and NTCP matrices, which are presented as colour maps superimposed on the corresponding CT slice. There is a set of parameters used for TCP/NTCP calculations which can be defined by the user.

Conclusion

Our application is a prototype of an evaluation tool. Although limited to a single plane of the treatment plan, it is believed to be a starting point for further development.     

Development and Efficacy of Real-Time PCR in the Diagnosis of Vivax Malaria Using Field Samples in the Republic of Korea

The development of sensitive, rapid, and accurate diagnostic methods for vivax malaria is essential for the effective control of malaria in the Republic of Korea, where vivax malaria patients usually show low parasitemia. In this study, a TaqMan-based real-time polymerase chain reaction (PCR) method was established and compared with other PCR-based assays, including nested PCR, loop-mediated isothermal amplification, and multiplex PCR, using samples from febrile patients with suspected vivax malaria. The established real-time PCR had a high sensitivity (99.6%) and specificity (100%). Therefore, this sensitive, specific, rapid, and quantitative real-time PCR method could be used for the routine diagnosis of vivax malaria in the laboratory of the Korea National Institute of Health.     

Parasite Biomass-Related Inflammation,Endothelial Activation,Microvascular Dysfunction and Disease Severity in Vivax Malaria

Plasmodium vivax can cause severe malaria, however its pathogenesis is poorly understood. In contrast to P. falciparum, circulating vivax parasitemia is low, with minimal apparent sequestration in endothelium-lined microvasculature, and pathogenesis thought unrelated to parasite biomass. However, the relationships between vivax disease-severity and total parasite biomass, endothelial autocrine activation and microvascular dysfunction are unknown. We measured circulating parasitemia and markers of total parasite biomass (plasma parasite lactate dehydrogenase [pLDH] and PvLDH) in adults with severe (n = 9) and non-severe (n = 53) vivax malaria, and examined relationships with disease-severity, endothelial activation, and microvascular function. Healthy controls and adults with non-severe and severe falciparum malaria were enrolled for comparison. Median peripheral parasitemia, PvLDH and pLDH were 2.4-fold, 3.7-fold and 6.9-fold higher in severe compared to non-severe vivax malaria (p = 0.02, p = 0.02 and p = 0.015, respectively), suggesting that, as in falciparum malaria, peripheral P. vivax parasitemia underestimates total parasite biomass, particularly in severe disease. P. vivax schizonts were under-represented in peripheral blood. Severe vivax malaria was associated with increased angiopoietin-2 and impaired microvascular reactivity. Peripheral vivax parasitemia correlated with endothelial activation (angiopoietin-2, von-Willebrand-Factor [VWF], E-selectin), whereas markers of total vivax biomass correlated only with systemic inflammation (IL-6, IL-10). Activity of the VWF-cleaving-protease, ADAMTS13, was deficient in proportion to endothelial activation, IL-6, thrombocytopenia and vivax disease-severity, and associated with impaired microvascular reactivity in severe disease. Impaired microvascular reactivity correlated with lactate in severe vivax malaria. Findings suggest that tissue accumulation of P. vivax may occur, with the hidden biomass greatest in severe disease and capable of mediating systemic inflammatory pathology. The lack of association between total parasite biomass and endothelial activation is consistent with accumulation in parts of the circulation devoid of endothelium. Endothelial activation, associated with circulating parasites, and systemic inflammation may contribute to pathology in vivax malaria, with microvascular dysfunction likely contributing to impaired tissue perfusion.     

Effects of cadmium exposure on lipid peroxidation and the antioxidant system in fourth-instar larvae of Propsilocerus akamusi (Diptera: Chironomidae) under laboratory conditions

Enzymatic antioxidants such as selenium-dependent glutathione peroxidase (GPx), glutathione transferase (GST), glutathione reductase (GR), and superoxide dismutases (SOD), as well as the concentration of hydrogen peroxide (H2O2) and malondialdehyde (MDA, an indicator of lipid peroxidation) were determined to identify which antioxidant enzymes participate in the efficient scavenging of ROS generated upon exposure to high doses of Cd2+ in fourth-instar Propsilocerus akamusi (Tokuna) (Diptera: Chironomidae) larvae after 72-h exposure. A significant increase in MDA levels and a change in GR and GPx activities in the Cd(2+)-treated P. akamusi were observed. The MDA in 25.0 and 50.0 mmol/liter treatments was significantly higher than that of the control dose after 72 h exposure. GPx activity was significantly induced by Cd2+ exposure only in the 50.0-mmol/liter treatment with a 0.59-fold increase in the control. All doses of Cd2+ significantly suppressed GR activity compared with the findings for the control dose, with an inhibited rate up to 0.55-fold in the 25.0 mmol/liter Cd2+ treatment. SOD and GST activities were not altered. The results indicate that Cd2+ can induce oxidative stress as indicated by the changes in lipid peroxidation and antioxidant status. For P. akamusi, an increase in the dose that the threshold needed for defense (namely, MDA level and GPx activity) activation was achieved. From this, organisms can be hypothesized to enable cells to avoid oxidant stress up to a certain extent where damage is again measurable (higher Cd2+ concentration).     

A mathematical model for the transmission of Plasmodium vivax malaria

We have proposed a mathematical model for the transmission of Plasmodium vivax malaria quantitatively, which is adjusted to the infected region, Guadalcanal, in the Solomon Islands. The simulation of a transmission model will be instrumental in planning the malaria control strategy. A characteristic of the life cycle of P. vivax is that a sporozoite injected into the blood stream by a mosquito bite may sometimes stay in a hepatocyte as a hypnozoite. Therefore, we have incorporated a phenomenon of renewed infections caused by a relapse into the transmission model. Also through the simulations we have attempted to evaluate the decline in prevalence caused by the programs of selective mass drug administration (MDA) and vector control such as the distribution of permethrin-treated bednets. The simulations have indicated that the concentrated repetition of MDA at 1-week intervals would reduce the prevalence of vivax malaria swiftly in the beginning and would keep the parasite rate below 1% for a few years but the prevalence would increase thereafter. In contrast, the parasite rate would remain below 1% for a long time if a trial of 1 or 2 times MDA is accompanied with some reduction of the vectorial capacity by the enforcement of vector control. In any case, it is important to beware of relapse cases because even after the execution of MDA it takes a long time to decrease the proportion of hypnozoite carriers.     

Clinical impact of vivax malaria: A collection review

BackgroundPlasmodium vivax infects an estimated 7 million people every year. Previously, vivax malaria was perceived as a benign condition, particularly when compared to falciparum malaria. Reports of the severe clinical impacts of vivax malaria have been increasing over the last decade.Methods and findingsWe describe the main clinical impacts of vivax malaria, incorporating a rapid systematic review of severe disease with meta-analysis of data from studies with clearly defined denominators, stratified by hospitalization status. Severe anemia is a serious consequence of relapsing infections in children in endemic areas, in whom vivax malaria causes increased morbidity and mortality and impaired school performance. P. vivax infection in pregnancy is associated with maternal anemia, prematurity, fetal loss, and low birth weight. More than 11,658 patients with severe vivax malaria have been reported since 1929, with 15,954 manifestations of severe malaria, of which only 7,157 (45%) conformed to the World Health Organization (WHO) diagnostic criteria. Out of 423 articles, 311 (74%) were published since 2010. In a random-effects meta-analysis of 85 studies, 68 of which were in hospitalized patients with vivax malaria, we estimated the proportion of patients with WHO-defined severe disease as 0.7% [95% confidence interval (CI) 0.19% to 2.57%] in all patients with vivax malaria and 7.11% [95% CI 4.30% to 11.55%] in hospitalized patients. We estimated the mortality from vivax malaria as 0.01% [95% CI 0.00% to 0.07%] in all patients and 0.56% [95% CI 0.35% to 0.92%] in hospital settings. WHO-defined cerebral, respiratory, and renal severe complications were generally estimated to occur in fewer than 0.5% patients in all included studies. Limitations of this review include the observational nature and small size of most of the studies of severe vivax malaria, high heterogeneity of included studies which were predominantly in hospitalized patients (who were therefore more likely to be severely unwell), and high risk of bias including small study effects.ConclusionsYoung children and pregnant women are particularly vulnerable to adverse clinical impacts of vivax malaria, and preventing infections and relapse in this groups is a priority. Substantial evidence of severe presentations of vivax malaria has accrued over the last 10 years, but reporting is inconsistent. There are major knowledge gaps, for example, limited understanding of the underlying pathophysiology and the reason for the heterogenous geographical distribution of reported complications. An adapted case definition of severe vivax malaria would facilitate surveillance and future research to better understand this condition.

Elizabeth A Ashley and colleagues describe the main clinical impacts of vivax malaria globally.     

Proteomic Analysis of Haptoglobin and Amyloid A Protein Levels in Patients with Vivax Malaria

Advancements in the field of proteomics have provided great opportunities for the development of diagnostic and therapeutic tools against human diseases. In this study, we analyzed haptoglobin and amyloid A protein levels of vivax malaria patients with combinations of depletion of the abundant plasma proteins, 2-dimensional gel electrophoresis (2-DE), image analysis, and mass spectrometry in the plasma between normal healthy donors and vivax malaria patients. The results showed that the expression level of haptoglobin had become significantly lower or undetectable in the plasma of vivax malaria patients due to proteolytic cleavage when compared to healthy donors on 2-DE gels. Meanwhile, serum amyloid A protein was significantly increased in vivax malaria patient''s plasma with high statistical values. These 2 proteins are common acute phase reactants and further large scale evaluation with a larger number of patient''s will be necessary to establish the possible clinical meaning of the existential changes of these proteins in vivax malaria patients. However, our proteomic analysis suggests the feasible values of some plasma proteins, such as haptoglobin and serum amyloid A, as associating factor candidates for vivax malaria.     

Coadministration of melatonin and estradiol in rats: effects on oxidant status.

This study was designed to investigate the effects of melatonin and estradiol (E2) on lipid peroxidation and antioxidant defense enzymes in blood and liver tissue when administered in vivo. Wistar albino rats were divided into three experimental groups and treated with either estradiol (25 mg/kg bw, s.c.), melatonin (i. p.), or melatonin plus E2, whereas control animals had diluent injections only. Melatonin was given 10 mg/kg bw x 2 intraperitoneally 30 min before and 60 min after E2 treatment to the melatonin plus E2 group. Animals were sacrificed three hours after the estradiol injection, and their blood and liver tissues were prepared for biochemical analyses. Tissue malondialdehyde (MDA) levels and antioxidant enzyme activities--superoxide dismutase (SOD) and glutathione peroxidase (GPx)--were determined in the postmitochondrial fraction, and the results were compared. Estradiol injection caused significant increases in both MDA levels and GPx activity in liver. When melatonin was administered in combination with E2, the effect of estradiol on MDA levels was abolished. A significant decrement in SOD activity occurred in melatonin-treated animals. GPx activity in the blood of E2 plus melatonin-injected animals was significantly higher than those in control animals. Melatonin-treated animals exhibited relatively lower levels of SOD activity than those from the control and E2 plus melatonin groups. This indicates that estradiol could exert oxidant action resulting in an increment in tissue malondialdehyde levels. Enhanced activity of GPx in both liver and blood following melatonin injection may indicate the contribution of this neurohormone on the antioxidant defense.     

Influence of smoking on serum and milk malondialdehyde, superoxide dismutase, glutathione peroxidase, and antioxidant potential levels in mothers at the postpartum seventh day

The aim of the study was to investigate simultaneously serum and milk malondialdehyde (MDA) levels, superoxide dismutase (SOD), glutathione peroxidase (GPx) activities, and antioxidant potential (AOP) in active-smoking, passive-smoking, and nonsmoking mothers and to search if there is any difference between serum and milk oxidant/ antioxidant status caused by smoking. According to their smoking status, 60 mothers (age range: 20–35 yr) were classified into one of three groups: the active-smoking mothers (n=15), the passive-smoking mothers (n=22), and the nonsmoking mothers (n=23). Serum and milk MDA, SOD, GPx, and AOP values were determined in mothers on the postpartum seventh day by the spectrophotometric method. Serum Zn and Cu concentrations were determined by atomic absorption spectrophotometry (AAS). There was no significant difference in serum samples with respect to MDA (p=0.17), SOD (p=0.51) and AOP (p=0.36) levels, but there was a significant difference in serum GPx (p=0.002) levels among the study groups. The significant differences were also found in milk samples in terms of MDA (p=0.002) and SOD (p=0.011), but not in GPx (p=0.11) and AOP (p=0.29) levels among the study groups. No significant difference was seen in serum zinc concentration (p=0.49), but copper concentration differed significantly among the groups (p=0.005). These observations suggest that human milk is more vulnerable to oxidative stress and lipid peroxidation than serum samples in smoking mothers, even if they are passive smokers.