Cardiac malformations in children with congenital hypothyroidism

Congenital hypothyroidism (CH) is the most common endocrine disease in children, according to literature, infants with CH have an increased risk of associated congenital malformations (CM), especially cardiac defects (CD), compared to the general population. We retrospectively analyzed medical records of 255 patients with a positive screening result for CH in the period 1991-2016 followed at our Center. At the time of enrollment, the clinical examination included looking for the presence of heart murmurs and dysmorphic features. In all patients an echocardiography with cardiological evaluation were performed. Of all patients, 191 were included in the final analysis. Of these, 51.3% (98/191) presented an eutopic normally sized thyroid gland while 48.7% (93/191) showed a thyroid dysgenesis. Among the studied infants, 13.6% (26/191) presented CD. The most frequent cardiac anomaly was atrial septal defect (ASD) which was found in 65.4% (17/26) of patients with CD. Other defects were ventricular septal defect (VSD), patent ductus arteriosus (PDA), pulmonary valve stenosis (PvS), transposition of the great vessels (TGV), aortic valve stenosis (AvS). Six patients had multiple defects. In the analysed group, there was no significant relation with sex, type of CH, median blood-TSH (b-TSH) and serum-TSH (s-TSH) values and frequency of CD. There is a high prevalence of CD in CH, indicating the need of routine echocardiography in these patients to achieve an early diagnosis and management of CD.

Hypertension in childhood

Hypertension is a growing health problem in children, and it is an important parameter of cardiovascular risk for adults. It is classified as primary (influenced by obesity, sedentary lifestyles and poor-quality food) or secondary to underlying causes. The AAP 2017 guidelines recommend measuring blood pressure every year from the age of three and in children under the age of three only if they have known risk factors. The measurement of infantile hypertension is relatively complicated and instable and, for this reason, ambulatory blood pressure monitoring (ABPM) and multiple office BP measurement (mOBPM), especially in infants who are not collaborating are indicated. High blood pressure may have an adverse effect on the heart, the vessels, the kidney, and the central nervous system so it is important recognize it and act promptly. Hypertension is initially treated with lifestyle changes such as weight loss, a healthy diet, and regular exercise, but, if non-pharmacological interventions have failed, a pharmacological treatment with angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, calcium channel blockers, thiazide diuretics and/or beta blocker may be indicated.

Prevalence of elevated pulmonary artery systolic pressure in Down Syndrome young patients with and without congenital heart disease

This study examined the prevalence and distribution of elevated systolic pulmonary arterial pressure, measured by echocardiography, in young patients with down syndrome associated or not with congenital heart disease and surgical correction during childhood. Pulmonary artery systolic pressure, computed by regurgitant tricuspid flow velocity evaluation, is the most frequently used parameter for the screening of pulmonary hypertension. Down syndrome and congenital heart disease often coexist and the probability to detect elevated systolic pulmonary arterial pressure in this setting is high. However, little is known about the evaluation of pulmonary arterial pressure during growth of patients with down syndrome with or without congenital heart disease. We enrolled 47 young patients (55% of male sex; mean age: 18.4 ± 6.0 years), 40 with congenital heart disease and 7 without a cardiac defect. Systolic pulmonary arterial pressure was assessed by echocardiography. No difference was found in the population dichotomized by presence or absence of CHD. Only male sex (p=0.000), highly sensitive troponin-T (P=0.027), tricuspid annular plane systolic excursion (TAPSE, p=0.045) and sPAP (p=0.004) were elevated in surgical group. The ASD was found as, the most common structural abnormality in our patients (50%), followed by VSD (27.5%) and complex CHD (such as complete atrioventricular canal defect, CAVC = 25% and Fallot disease = 15%). Furthermore, about 45% of patients had the combined defect. Only 37.5% of patients underwent to corrective surgery during the first months of life. We observed a significantly increase of sPAP values in patients with complex CHD, such as CAVC (p=0.019) and Fallot disease (p=0.001) but, in the following multivariate analysis performed in the patients with CHD, only Fallot disease remains as independent predictors of elevated values of sPAP (p=0.022). An elevated systolic pulmonary arterial pressure may represent the key screening tool in the diagnostic assessment of suspect pulmonary arterial hypertension in high risk population with down syndrome regardless the presence of congenital heart disease.

PPHN and oxidative stress: a review of literature

Persistent pulmonary hypertension of the neonate is a multifactorial condition characterized by maladaptive pulmonary vascular remodeling and abnormal contractile reactivity. This review evaluates the role of oxidative stress and antioxidant treatment on the persistent pulmonary hypertension of the neonate.

Hemodialysis in children: how, when and why

End-stage renal diseases requiring chronic dialysis are rare in childhood and adolescence, but they are associated with high mortality and impaired quality of life (1, 2). The most common disease that causes chronic kidney disease (CKD) is primary glomerular disease (GD), followed by congenital abnormalities of the kidney and urinary tract, cystic, hereditary or congenital disorders and, more rarely, secondary GD. However, patients with secondary GD, urologic disorders, and metabolic diseases have greater mortality risk than patients with primary GD (3). Here, we focused on the different options of treatment available, and specifically we compared peritoneal dialysis and hemodialysis, showing pros and cons between them.

Unusual presentation of Henoch-Schönlein purpura

Henoch Schonlein Purpura (HSP) is a systematic IgA-mediated vasculitic disease that affects the small vessels of the skin, the joints, the gastrointestinal tract and the kidneys (1). It is the most common childhood vaculitis, with an incidence estimated at 3-26 per 100,000 children, and with a male-to-female ratio of 2:1 (2-6). The 90% of patients are under 10 years of age, with a mean age of 4 years (4). It seems to be most common in fall and winter in children, and summer and winter in adults (7). Recent studies suggested a strong genetic predisposition in individuals with immunoglobulin Avasculitis (IgAV) associated to HLA class II region. Clinically, the non-thrombocytopenic purpura often located on lower extremities and buttocks is the essential element for the diagnosis of HSP. Treatment is supportive, because the disease is usually benign and self-limited. Indeed, in children, the prognosis is good, with a self-limited course and without any complications and after a median follow-up of 12 months, complete recovery was obtained in 83% of the IgAV patients (4, 8). The aim of our study is to describe some atypical presentations of the HSP in children.

Renal anomalies in newborns with vacterel association: case series and literature review

Nocturnal enuresis (NE) was defined by the World Health Organization (ICD-10) and the American Psychiatric Association (DSM-5) as bed-wetting in children aged >5 years. In cases of mental retardation, the developmental age may be equivalent to 5 years. In this review, we focus on the current knowledge about the etiology of enuresis and the most recent therapeutical options. Both non-pharmacological and pharmacological therapies are included, although the relative effectiveness of each remains uncertain. To date, motivational, alarm and drug therapies are the mainstay of treatment. Alarm therapy remains the first-line treatment modality for NE, while desmopressin is the most commonly used medical treatment.

Local therapy with ozone in the management of the exit site in a patient undergoing peritoneal dialysis

The natural history of children with end stage renal disease is dialysis until a transplant can be done. There are two types of dialysis: hemodialysis and peritoneal dialysis (1). Peritoneal dialysis is preferred in young children because getting the vascular access for hemodialysis is challenging (2). Catheters should be surgically placed in a paramedian or lateral abdominal region with an extremity located in Douglas' pouch.

Nephrotic syndrome: immunological mechanisms

Nephrotic Syndrome (NS) is a rare diseases (around 2-7 cases per 100.000 children per year) characterized by proteinuria ≥50 mg/kg/day (or ≥40 mg/m2/h) or a proteinuria/creatininuria ratio >2 (mg/mg); hypoalbuminaemia less than 25 g/l and edema. The protein leakage, with the consequent hypoalbunaemia and edema, due to podocyte alterations may be caused by genetic diseases, immunological mechanisms, infections, toxins or malignancy. However, most commonly the exact etiology is unknow. The idiopathic NS may be classified based on response to corticosteroid therapy or the hytological appearance. The first classification identifies steroid-resistant NS (no response after 4 weeks of steroid therapy); frequently relapsing NS (≥ 2 relapses in first 6 months or ≥4 relapses in 1-year); steroid dependent NS (relapses during steroid decalage or within 2 weeks from steroid therapy interruption). The hystological classification is based on light and electron microscopy after renal biopsy, which is indicated in case of onset disease before 1 year or after 12 years of age. Macroscopic hematuria: persistent hypertension and/or microscopic hematuria and/or low plasma C3 renal failure not related to hypovolemia; steroid resistence: secondary or relatedsyndromes NS. Minimal change disease (MCD) is the most common form of idiopahtic NS in children, with good response to steroid treatment, and it is characterized by normal glomerular appearance on light microscopy and evidence of podocyte foot alterations on electron microscopy, due to immunological related damage. Focal segmental glomerulosclerosis (FSGS) is described inidiopahtic NS, particularly in steroiddependent or steroid-resistant forms, and is characterized by evidence of focal glomerular damage with secondary sclerosis and adhesion with Bowman's capsule; the electron appearance is the same of MCD one. Recent authors hypotizethat the FSGS is an evolution of MCD. These 2 idiopathic NS forms may be expression of the same immunological disease, with 2 different severity grades; so they may be considered different moments of the same disease spectrum. Less common idiopathic NS forms are membrano proliferative glomerulonephritis; membranous nephropathy; IgM-nephropathy; C1q nephropathy and thin basement membrane disease (1, 2, 3).

Human herpesviruses-6 and -7 encephalitis in immunocompetent infants: are they really so uncommon?

Human herpesviruses-6 and -7 (HHV-6 and 7) are considered uncommon causes of central nervous system infection and may occasionally cause encephalitis in young infants, however, the clinical syndrome and incidence are not well defined. In immunosuppressed hosts, reactivation is associated with a worse outcome such as encephalitis, hepatitis, or graft rejection. In immunocompetent hosts, this persistent infection is generally of no consequence. We report 4 cases of immunocompetent critically ill children, affected by HHV-6 and -7 encephalitis, admitted to our Pediatric Intensive Care Unit. In three patients, herpesvirus polymerase chain reaction in blood and cerebrospinal fluid was positive for HHV- 6, while one patient was positive for HHV-7. In our cases, a typical clinical picture of viral infection was not present but neurological symptoms were predominant. In all 4 children, neurological involvement rapidly regressed after acyclovir therapy. In this report, we offer evidence that HHV-6 and -7 primary infections can cause several clinical manifestations, such as encephalitis, also in immunocompetent hosts. In our experience, children with neurological symptoms suggestive of viral encephalitis should be fully investigated for these two viruses.

ALMOND MILK: A POTENTIAL THERAPEUTIC WEAPON AGAINST COW’S MILK PROTEIN ALLERGY

Food allergy is defined as an adverse health effect arising from a specific immune response that occurs reproducibly following exposure to a given food. Cow’s milk protein allergy results from an immunological reaction to one or more milk proteins. The principle key in the treatment of cow’s milk protein allergy is the dietary elimination of cow’s milk protein. Although hydrolyzed and elemental formulas are appropriate replacements, other milk products, including almond milk adequately integrated, could be administered. Here, in the light of encouraging results from our study, we focused on the anti-inflammatory and anti-oxidant properties of almond milk and we also believe that almond milk might be considered as a potential alternative in cow’s milk protein allergy treatment.

POTENTIAL USE OF MELATONIN IN PROCEDURAL ANXIETY AND PAIN IN CHILDREN UNDERGOING BLOOD WITHDRAWAL

The recognition of the value of pain, especially in the pediatric population, has increased over the last decade. It is known that pain-related anxiety can increase perceived pain intensity. There are several different approaches to the treatment of pre-procedural anxiety and procedural pain in children. Melatonin, a neurohormone with the profile of a novel hypnotic-anaesthetic agent, plays an important role in anxiolysis and analgesia. This study investigated the effects of oral melatonin premedication to reduce anxiety and pain in children having blood samples taken. The investigations were carried out on 60 children, aged 1-14 years, divided into 2 equal groups. Using a computer-generated randomization schedule, patients were given either melatonin orally (0.5 mg/kg BW, max 5 mg) or placebo 30 min before blood draw. Pre-procedural anxiety was assessed using the scale from the Children’s Anxiety and Pain Scales, while procedural pain used the Face, Legs, Activity, Cry and Consolability assessment tool for children under the age of 3 years, Faces Pain Scale-Revised for children aged 3-8 years and Numeric Rating Scale for children over the age of 8 years. Oral administration of melatonin before the blood withdrawal procedure significantly reduced both anxiety (p<0.0005) and pain levels than placebo (p<0.0002 for children under 3 years and p<0.0039 for children over 3 years). These data support the use of melatonin for taking blood samples due to its anxiolytic and analgesic properties. Further studies are needed to support the routine use of melatonin to alleviate anxiety and pain in pediatric patients having blood samples taken.

ATOPIC DERMATITIS: MELATONIN AS POTENTIAL TREATMENT

Atopic dermatitis (AD) is a chronic relapsing-remitting inflammatory skin disorder, characterized by a skin barrier dysfunction resulting in epidermal damage and altered permeability to allergens and microbes. Traditionally, the immunological mechanism involving the Th1-Th2 paradigm is considered central in the pathogenesis of AD. However, oxidative stress is, currently, recognized as a fundamental predisposing stimulus for AD. Several therapeutic approaches have been proposed as treatment, including the use of melatonin. This indolamine, through widespread expression and pleiotropic activity of the cutaneous melatoninergic system, may counteract environmental and endogenous stressors, regulate the immune response, decrease oxidative stress, and, finally, promote skin integrity. In the light of its pleiotropic effects, melatonin could represent a potential and alternative therapeutic approach in patients with AD.

HIGH-MOBILITY GROUP BOX 1 IN ALLERGIC AND NON ALLERGIC UPPER AIRWAY INFLAMMATION

High mobility group box 1, an evolutionary ancient protein conserved in the eukaryotic kingdom, exerts intra- and extra- cellular functions, orchestrating a homeostatic defensive response in challenged tissues. Its action associated with various inflammatory cells is essential for the occurrence, progression, and persistence of asthma, rhinitis, and nasal polyposis. The recent discovery of High mobility group box 1, as a critical mediator of inflammation, stimulated an increasing interest in the field of inflammation research, suggesting new therapies for atopic and non-atopic inflammatory processes.

Colonic stenosis post-necrotizing enterocolitis in term newborn with acquired cytomegalovirus infection

Necrotizing enterocolitis is a gastrointestinal emergency typical of premature infants. Intestinal strictures infrequently complicate medical or surgical treatment of necrotizing enterocolitis. Postnatal cytomegalovirus infection with gastrointestinal linvolvement has occasionally been described in subjects with necrotizing enterocolitis. We report the case of a full term infant presenting necrotizing enterocolitis, acquired cytomegalovirus infection and post necrotizing enterocolitis colonic stricture.List of abbreviations: necrotizing enterocolitis = NEC,cytomegalovirus = CMV.

Airways allergic inflammation and L. reuterii treatment in asthmatic children

Recently, it has been hypothesized that the oral administration of specific live probiotic strains may have therapeutic potential in the treatment of allergic inflammation. The aim of this study was to evaluate the effect of the oral L. reuteri DSM 17938 administration (1X108CFU), in airways allergic inflammation in mild persistent asthmatic children. In this DBPC randomized study we selected 50 children (6-14 years old), affected by mild persistent asthma (GINA step 2) and allergic to HDM. At the run-in period (T-2), the children were submitted to medical examination, prick tests for the main respiratory allergens, spirometry and children asthma control test (C-ACT). We selected only the children with well controlled asthma (C-ACT >19 and FEV1> 80%). After two weeks (T0) the children were allocated into two groups, the FeNO was measured and the breath condensate was collected. Group A children were treated with the placebo (5 drops per day) and Group B children with L. reuteri (108CFU =5 drops per day) for 60 days. After the treatment period (T1), all patients were evaluated by medical examination, C-ACT, spirometry, FeNO measurement and exaled breath condensate analysis. The FeNO values showed a significant reduction (p=0,045) in L. reuteri group but not in the placebo group at the end of the treatment (T1). Furthermore, the cytokines exam showed an increase in IL-10 levels (p less than 0.05) and a significant reduction in IL-2 levels (p less than 0.05) only in L. reuteri group at T1. No significant differences in FEV1 values and C-ACT score were found in both groups. In conclusion, these data showed that L. reuteri (108 CFU) was effective in reducing bronchial inflammation in asthmatic children. No significant effect was found on FEV1 values and C-ACT score, probably because we selected children with well controlled asthma.

Atopy as a risk factor for thyroid autoimmunity in children

Recently, there has been considerable interest in the relationship between allergic and autoimmune diseases. We evaluated the prevalence of thyroid autoimmunity in 566 children affected by atopic dermatitis (AD), urticaria, rhinitis, chronic cough, and asthma. Our results suggest that allergy and autoimmunity can be two potential outcomes of dysregulated immunity. It is tempting to speculate that NK Th2 cells can favour asthma onset and at the same time improve thyroid autoimmunity.

Effect of weight reduction on leptin, total ghrelin and obestatin concentrations in prepubertal children

The aim of the study was to evaluate fasting levels of glucose, insulin, leptin, total ghrelin, and obestatin in a group of prepubescent obese children before and after weight loss. We enrolled 64 prepubescent obese children, but only 35 completed the study (mean age 7.6 +- 0.9 years, 19 females) and 20 normal-weight prepubescent children as controls. Fasting plasma concentration of glucose, insulin, Homeostasis Model assessment for insulin resistance (HOMA-IR), and leptin, total ghrelin, and obestatin levels were measured at baseline and after a 6-month lifestyle intervention (i.e. improved nutrition and increased physical activity). At baseline, obese children showed significantly (p less than 0.001) higher leptin and obestatin levels, and lower total ghrelin concentrations than control subjects. Weight loss significantly (p less than 0.001) diminished plasma leptin and insulin levels and increased ghrelin and obestatin concentrations. Weight loss in prepubescent children is associated with a significant change in leptin, ghrelin and obestatin concentrations. These results confirm the hypothesis that levels of these hormones are closely associated with obesity in childhood and might take part, as consequence but not as a cause, in glucose, fat, and energy metabolism.

Oxidative stress in resuscitation and in ventilation of newborns

The lungs of newborns are especially prone to oxidative damage induced by both reactive oxygen and reactive nitrogen species. Yet, these infants are often 1) exposed to high oxygen concentrations, 2) have infections or inflammation, 3) have reduced antioxidant defense, and 4) have high free iron levels which enhance toxic radical generation. Oxidative stress has been postulated to be implicated in several newborn conditions with the phrase "oxygen radical diseases of neonatology" having been coined. There is, however, reason to believe that oxidative stress is increased more when resuscitation is performed with pure oxygen compared with ambient air and that the most effective ventilatory strategy is the avoidance of mechanical ventilation with the use of nasopharyngeal continuous positive airway pressure whenever possible. Multiple ventilation strategies have been attempted to reduce injury and improve outcomes in newborn infants. In this review, the authors summarise the scientific evidence concerning oxidative stress as it relates to resuscitation in the delivery room and to the various modalities of ventilation.

Melatonin reduces oxidative stress in surgical neonates

BACKGROUND/PURPOSE

Cytokines are inflammatory mediators found in the circulation after surgery. Newborns have less protection against oxidation and are very susceptible to free radical oxidative damage. Melatonin has been reported recently to reduce oxidative stress in neonates with sepsis, asphyxia, and respiratory distress. The aim of this study has been to determine if melatonin would lower interleukin (IL)-6, IL-8, tumor necrosis factor alpha (TNF-alpha) and nitrite/nitrate (NOx) levels and modify serum inflammation parameters, improving the clinical course of surgical neonates.

METHODS

Ten newborns (group 1), 5 with surgical malformations and respiratory distress (group 1a) and 5 with isolated abdominal surgical malformations (group 1b) received a total of 10 doses of melatonin (10 mg/kg) at defined times interval for 72 hours. The treatment was started within 3 hours after the end of surgery. Ten surgical neonates (group 2), did not receive melatonin. Twenty healthy neonates (group 3) served as control. Blood samples were collected at the end of operation; before treatment with the antioxidant; and 24 hours 72 hours, and 7 days after start of treatment with melatonin or placebo, respectively.

RESULTS

Postoperative value of cytokines and NOx levels of groups 1 and 2 were significantly higher than group 3. Compared with group 1b, group 2 displayed significantly higher cytokines and NOx levels at 24 hours, 72 hours, and at 7 days. In group 1a the immediate postoperative values of cytokines were significantly higher than group 1b and group 2, but a significant improvement was observed after administration of melatonin with significantly lower levels of IL-6 and IL-8 with respect to group 2. An improvement of clinical outcome was observed by progressive reduction of clinical parameters of inflammation.

CONCLUSIONS

Melatonin reduces cytokines and NOx levels showing potent antioxidant properties with improvement in clinical outcome. Further studies are warranted to define, on larger numbers, the role of melatonin in surgical patients.

Can the administration of antithrombin III decrease the risk of cerebral hemorrhage in premature infants?

This study was carried out to determine whether the administration of antithrombin III decreases the risk of intraventricular hemorrhage in premature infants. In a randomized study, 60 infants born before 30 weeks of gestation were assigned to receive a loading dose of antithrombin III or placebo. There was no significant difference in the incidence of intraventricular hemorrhage between the antithrombin III and the placebo group (27.5 vs. 32%). Partial thromboplastin time, Quick's prothrombin time and platelet count were also not significantly different between the 2 groups. We conclude that the administration of antithrombin III during the first 2 days of life does not decrease incidence of intraventricular hemorrhage. Antithrombin III is a very expensive therapy and its benefits should be carefully investigated before being recommended as valuable therapy.

Induction of lipid peroxidation in hamster organs by the carcinogen cadmium: melioration by melatonin

Cadmium is a well-known human carcinogen. Lipid peroxidation is involved in cadmium-related toxicity and carcinogenesis. Melatonin is an effective antioxidant and free radical scavenger. The potential protective effects of melatonin against cadmium-induced lipid peroxidation in hamster brain, heart, kidney, testes, lung, and liver were examined. Lipid peroxidation was induced by intraperitoneal injection of cadmium chloride [single dose of 1 mg/kg body weight (bw)]. To test whether melatonin would protect against the toxicity of the carcinogen, the melatonin was injected peritoneally at a dose of either 15 mg/kg bw or 5 mg/kg bw, 0.5 h before cadmium treatment and thereafter at 8 h intervals during the day in the 48 h interval following the cadmium injection. One group of hamsters received only a single melatonin injection (a dose of 15 mg/kg bw, 30 min prior to cadmium). Forty-eight hours after cadmium injection, lipid peroxidation increased in brain, heart, kidney, testes, and lung. Either multiple injections of melatonin at both the 5 and 15 mg/kg bw doses, or a single injection of 15 mg/kg bw, prevented the cadmium-related increases in lipid peroxidation in brain, heart and lung. Cadmium-induced lipid peroxidation in kidney was prevented by melatonin when it was given as a single dose of 15 mg/kg bw. Melatonin slightly, but not significantly, reduced cadmium-induced lipid peroxidation in testes. It is concluded that cadmium toxicity, at least with regard to the resulting lipid peroxidation, is reduced by administering melatonin.

Effects of melatonin treatment in septic newborns

Free radicals have been implicated in the pathogenesis of neonatal sepsis and its complications. This study was conducted to determine the changes in the clinical status and the serum levels of lipid peroxidation products [malondialdehyde (MDA) and 4-hydroxylalkenals (4-HDA)] in 10 septic newborns treated with the antioxidant melatonin given within the first 12 h after diagnosis. Ten other septic newborns in a comparable state were used as "septic" controls, while 10 healthy newborns served as normal controls. A total of 20 mg melatonin was administered orally in two doses of 10 mg each, with a 1-h interval. One blood sample was collected before melatonin administration and two additional blood samples (at 1 and 4 h) were collected after melatonin administration to assess serum levels of lipid peroxidation products. Serum MDA + 4-HDA concentrations in newborns with sepsis were significantly higher than those in healthy infants without sepsis; in contrast, in septic newborns treated with melatonin there was a significant reduction (p < 0.05) of MDA + 4-HDA to the levels in the normal controls at both 1 and 4 h (p < 0.05). Melatonin also improved the clinical outcome of the septic newborns as judged by measurement of sepsis-related serum parameters after 24 and 48 h. Three of 10 septic children who were not treated with melatonin died within 72 h after diagnosis of sepsis; none of the 10 septic newborns treated with melatonin died. To our knowledge, this is the first study where melatonin was given to human newborns.

Increased levels of malondialdehyde and nitrite/nitrate in the blood of asphyxiated newborns: reduction by melatonin

Free radicals have been implicated in the pathogenesis of neonatal asphyxia and its complications. This study measured a product of lipid peroxidation, malondialdehyde, and the nitrite/nitrate levels in the serum of 20 asphyxiated newborns before and after treatment with the antioxidant melatonin given within the first 6 hr of life. Ten asphyxiated newborns received a total of 80 mg of melatonin (8 doses of 10 mg each separated by 2-hr intervals) orally. One blood sample was collected before melatonin administration and two additional blood samples (at 12 and 24 hr) were collected after giving melatonin. A third group of healthy newborn children served as controls. Serum malondialdehyde and nitrite+nitrate concentrations in newborns with asphyxia before treatment were significantly higher than those in infants without asphyxia. In the asphyxiated newborns given melatonin, there were significant reductions in malondialdehyde and nitrite/nitrate levels at both 12 and 24 hr. Three of the 10 asphyxiated children not given melatonin died within 72 hr after birth; none of the 10 asphyxiated newborns given melatonin died. The results indicate that the melatonin may be beneficial in the treatment of newborn infants with asphyxia. The protective actions of melatonin in this study may relate to the antioxidant properties of the indole as well as to the ability of melatonin to increase the efficiency of mitochondrial electron transport.

Individual and synergistic antioxidative actions of melatonin: studies with vitamin E, vitamin C, glutathione and desferrioxamine (desferoxamine) in rat liver homogenates

The pharmacological effects of melatonin, vitamin E, vitamin C, glutathione and desferrioxamine (desferoxamine) alone and in combination on iron-induced membrane lipid damage in rat liver homogenates were examined by estimating levels of malondialdehyde and 4-hydroxyalkenals (MDA+4-HDA). Individually, melatonin (2.5-1600 microM), vitamin E (0.5-50 microM), glutathione (100-7000 microM) and desferrioxamine (1-8 microM) inhibited lipid peroxidation in a concentration-dependent manner. Vitamin C had both a pro-oxidative (25-2000 microM) and an antioxidative (2600-5000 microM) effect. The IC50 (concentration that reduces damage by 50%) values were 4, 10, 426, 2290 and 4325 microM for vitamin E, desferrioxamine, melatonin, glutathione and vitamin C, respectively. The synergistic actions of melatonin with vitamin C, vitamin E, and glutathione were systematically investigated. When melatonin was combined with vitamin E, glutathione, or vitamin C, the protective effects against iron-induced lipid peroxidation were dramatically enhanced. Even though melatonin was added at very low concentrations, it still showed synergistic effects with other antioxidants at certain concentrations. Furthermore, melatonin not only reversed the pro-oxidative effects of vitamin C, but its efficacy in reducing lipid peroxidation was improved when it was combined with pro-oxidative concentrations of vitamin C. The results provide new information in terms of the possible pharmacological use of the combination of melatonin and classical antioxidants to treat free radical-related conditions.

Respiratory distress syndrome in the newborn: role of oxidative stress

Reactive oxygen and nitrogen species are generated by several inflammatory and structural cells of the airways. These oxidant species have important effects on a variety of lung cells as regulators of signal transduction, activators of key transcription factors and modulators of gene expression and apoptosis. Thus, increased oxidative stress accompanied by reduced endogenous antioxidant defenses may play a role in the pathogenesis of a number of inflammatory pulmonary diseases, including respiratory distress syndrome (RDS) in the newborn. There obviously are conflicting reports on the effect of oxygen, ventilation and nitric oxide (NO) on RDS and, thus, the question arises as what the neonatologist should do when confronted with a newborn with RDS. Clearly, utilizing lung protective strategies requires compromises between gas exchange goals and potential toxicities associated with over-distension, derecruitment of lung units and high oxygen concentrations. The results discussed in this brief review suggest rigorous clinical tests with antioxidants which may help to define the mechanisms associated with RDS and which could lead to new treatment strategies.

Melatonin attenuates estradiol-induced oxidative damage to DNA: relevance for cancer prevention

Estrogens exert pro-oxidative effects and have been shown to damage DNA, potentially leading to cancer. Melatonin is a well-known antioxidant, free radical scavenger, and oncostatic agent. Changes in the levels of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodGuo), an index of DNA damage, and the levels of malondialdehyde + 4-hydroxyalkenals, an index of lipid peroxidation, were measured in kidneys, liver, and testes from hamsters treated with E2 (75 mg/kg body wt) and were collected 3 or 5 hr later. Other animals were treated with melatonin (15 mg/kg body wt, 30 min before and 120 min after E2 treatment) or were given both compounds. Additionally, lipid peroxidation was measured in liver homogenates exposed to ferrous sulfate (15 microM) in vitro. E2 treatment caused an increase in 8-oxodGuo levels in kidneys collected 5 hr after E2 administration, and in liver 3 hr after estrogen treatment. Melatonin completely prevented E2-induced DNA damage in both organs. Melatonin alone or when given with E2 and examined 3 hr later decreased the base level of 8-oxodGuo in testes. A tendency for a reduction in in vivo lipid peroxidation was observed after treatment of hamsters with either melatonin, E2, or both compounds, with a statistically significant decrease being measured in the liver following E2 administration. In vitro exposure to iron significantly enhanced lipid peroxidation in hepatic homogenates from untreated, melatonin-treated, or E2-injected hamsters; in the hepatic homogenates of hamsters given both E2 and melatonin, ferrous sulfate failed to augment lipid peroxidation. Our results confirm the dual actions of estrogens relative to oxidative damage, i.e., estrogen increases oxidative destruction of DNA while reducing lipid peroxidation. Melatonin had antioxidative actions in reducing oxidative damage to both DNA and to membrane lipids. Melatonin completely prevented the damaging action of E2 on DNA and synergized with the steroid to reduce lipid peroxidation.

Relative efficacies of indole antioxidants in reducing autoxidation and iron-induced lipid peroxidation in hamster testes

Increased iron stores are associated with free radical generation and carcinogenesis. Lipid peroxidation is involved in DNA damage, thus indirectly participating in the early steps of tumor initiation. Melatonin and structurally related indoles are effective in protecting against oxidative stress. The aim of the study was to compare the relative efficacies of melatonin, N-acetylserotonin (NAS), indole-3-propionic acid (IPA), and 5-hydroxy-indole-3-acetic acid (5HIAA) in altering basal and iron-induced lipid peroxidation in homogenates of hamster testes. To determine the effect of the indoles on the autoxidation of lipids, homogenates were incubated in the presence of each agent in concentrations of 0.0, 0.01, 0.05, 0.1, 0.25, 0.5, 0.75, 1.0, 2.0, 2.5, or 5.0 mM. To study their effects on induced lipid peroxidation, homogenates were incubated with FeSO(4) (30 microM + H(2)O(2) (0.1 mM) + each of the indoles in the same concentrations as above. The degree of lipid peroxidation was expressed as concentrations of malondialdehyde + 4-hydroxyalkenals (MDA + 4-HDA) per mg protein. The indoles decreased both basal and iron-related lipid peroxidation in a concentration-dependent manner. Melatonin reduced basal MDA + 4-HDA levels when used at the concentrations of 0.25 mM or higher, and prevented iron-induced lipid peroxidation at concentrations of 1.0, 2.0, 2.5, or 5.0 mM. The lowest effective concentrations of NAS required to lower basal and iron-related lipid peroxidation were 0.05 mM and 0.25 mM, respectively. IPA, only when used in the highest concentrations of 2.5 mM or 5 mM inhibited basal lipid peroxidation levels and it was ineffective on the levels of MDA + 4-HDA due to iron damage. 5HIAA reduced basal lipid peroxidation when used at concentrations of 0.25 mM or higher, and it prevented iron-induced lipid peroxidation only at the highest applied concentration (5 mM). In conclusion, melatonin and related indoles at pharmacological concentrations protect against both the autoxidation of lipids as well as induced peroxidation of lipids in testes. In doing so, these agents would be expected to reduce testicular cancer that is initiated by products of lipid peroxidation.

Protective effects of melatonin in ischemic brain injury

Recent studies have demonstrated that melatonin is a scavenger of oxyradicals and peroxynitrite and an inhibitor of nitric oxide (NO) production. NO, peroxynitrite (formed from NO and superoxide anion), and poly (ADP-Ribose) synthetase (PARS) have been implicated as mediators of neuronal damage following focal ischemia. In the present study, we have investigated the effects of melatonin treatment in Mongolian gerbils subjected to cerebral ischemia. Treatment of gerbils with melatonin (10 mg kg(-1), 30 min before reperfusion and 1, 2, and 6 hr after reperfusion) reduced the formation of post-ischemic brain edema, evaluated by water content. Melatonin also attenuated the increase in the brain levels malondialdehyde (MDA) and the increase in the hippocampus of myeloperoxidase (MPO) caused by cerebral ischemia. Positive staining for nitrotyrosine was found in the hippocampus of Mongolian gerbils subjected to cerebral ischemia. Hippocampus tissue sections, from Mongolian gerbils subjected to cerebral ischemia, also showed positive staining for PARS. The degrees of staining for nitrotyrosine and for PARS were markedly reduced in tissue sections obtained from animals that received melatonin. Melatonin treatment increased survival and reduced hyperactivity linked to neurodegeneration induced by cerebral ischemia and reperfusion. Histological observations of the pyramidal layer of CA-1 showed a reduction of neuronal loss in animals that received melatonin. These results show that melatonin improves brain injury induced by transient cerebral ischemia.

Actions of melatonin in the reduction of oxidative stress. A review

Melatonin was discovered to be a direct free radical scavenger less than 10 years ago. Besides its ability to directly neutralize a number of free radicals and reactive oxygen and nitrogen species, it stimulates several antioxidative enzymes which increase its efficiency as an antioxidant. In terms of direct free radical scavenging, melatonin interacts with the highly toxic hydroxyl radical with a rate constant equivalent to that of other highly efficient hydroxyl radical scavengers. Additionally, melatonin reportedly neutralizes hydrogen peroxide, singlet oxygen, peroxynitrite anion, nitric oxide and hypochlorous acid. The following antioxidative enzymes are also stimulated by melatonin: superoxide dismutase, glutathione peroxidase and glutathione reductase. Melatonin has been widely used as a protective agent against a wide variety of processes and agents that damage tissues via free radical mechanisms.

Effects of tempol, a membrane-permeable radical scavenger, in a gerbil model of brain injury

There is evidence that the excessive generation of reactive-oxygen radicals contributes to the brain injury associated with transient, cerebral ischemia. This study investigates the effects of tempol, a small, water-soluble molecule, that crosses biological membranes, on the brain injury caused by bilateral occlusion and reperfusion of both common carotid arteries in the gerbil (BCO). Treatment of gerbils with tempol (30 mg/kg i.p. at 30 min prior to reperfusion and at 1 and 6 h after the onset of reperfusion) reduced the formation of post-ischemic brain oedema. Tempol also attenuated the increase in the cerebral levels of malondialdehyde (MDA) and the hippocampal levels of myeloperoxidase (MPO) caused by cerebral ischemia and reperfusion. The immunohistochemical analysis of the hippocampal region of brains subjected to ischemia-reperfusion exhibited positive staining for nitrotyrosine (an indicator of the generation of peroxynitrite) and poly(ADP-ribose) synthetase (PARS) (an indicator of the activation of this nuclear enzyme secondary to single strand breaks in DNA). In gerbils subjected to BCO, which were treated with tempol, the degree of staining for nitrotyrosine and PARS was markedly reduced. Tempol increased survival and reduced the hyperactivity (secondary to the ischemia-induced neurodegeneration) caused by cerebral ischemia and reperfusion. The loss of neurons from the pyramidal layer of the CA1 region caused by ischemia and reperfusion was also attenuated by treatment of gerbils with tempol. This is the first evidence that the membrane-permeable, radical scavenger tempol reduces the cerebral injury caused by transient, cerebral ischemia in vivo.

Myocardial ischaemia in neonates with perinatal asphyxia. Electrocardiographic, echocardiographic and enzymatic correlations

In asphyxiated neonates, hypoxia is often responsible for myocardial ischaemia. To evaluate cardiac involvement in neonates with respiratory distress, ECG and echocardiographic recordings were performed, and cardiac enzymes determined. These data were related to clinical presentation and patient outcome. Three groups of neonates were studied: 22 healthy newborn infants (group I) with 5 min Apgar scores > 9 and pH > 7.3; 15 neonates with moderate respiratory distress (group II) which had Apgar scores ranging between 7 and 9, and pH between 7.2 and 7.3; and 13 neonates with severe asphyxia, Apgar scores < 7, and pH < 7.2 (group III). The ECGs were evaluated according to the 4-grade classification proposed by Jedeikin et al. [8]. On the echocardiograms, fractional shortening and aortic flow curve parameters were taken into account. Serum creatine kinase (CK), creatine kinase-MB isoenzyme (CK-MB) and lactate dehydrogenase were determined. All of groups I and II survived, but 5 out of 13 in group III died within the 1st week. Grade 3 or 4 ECG changes were observed only in group III patients, while all group II and 3 patients of group I showed grade 2 ECG changes. Fractional shortening, peak aortic velocity and mean acceleration were significantly reduced in group III, whereas the only abnormality found in group II was a reduced fractional shortening. CK, CK-MB, CK-MB/CK ratio and lactate dehydrogenase were all increased in group III, while in group II only CK-MB and the CK-MB/CK ratio were abnormal. Severely asphyxiated newborn infants reflect relevant ischaemic electrocardiographic changes, depressed left ventricular function and marked cardiac enzyme increase. These alterations are far less pronounced in neonates with mild respiratory distress.