Early detection of acute kidney injury by serum cystatin C in critically ill children

BACKGROUND

We prospectively evaluated whether serum cystatin C (CysC) detected acute kidney injury (AKI) earlier than basal serum creatinine (Cr).

METHODS

In 107 pediatric patients at high risk of developing AKI, serum Cr and serum CysC were measured upon admission. Baseline estimated creatinine clearance (eCCl) was calculated using a CysC-based glomerular filtration rate (GFR) equation from a serum Cr measured at the pediatric intensive care unit (PICU) entrance.

RESULTS

The median age was 10 months (interquartile range, 3-36 months). Serum Cr, serum CysC, and eCCl (mean ± standard deviation [range]) were 0.5 ± 0.18 mg/dl (0.2-1.1 mg/dl), 0.53 ± 0.78 (0.01-3.7 mg/l), and 72.55 ± 28.72 (20.6-176.2) ml/min per 1.73 m(2), respectively. The serum CysC level in patients with AKI was significantly higher than children with normal renal function (p < 0.001). The values for the cut-off point, sensitivity, specificity, and the area under curve (AUC) were determined for CysC as 0.6 mg/l, 73.9 %, 78.9 %, and 0.92 [95 % confidence interval (0.82-1)], respectively, and for Cr the values were 0.4 mg/dl, 68 %, 46.2 %, and 0.39, [95 % confidence interval (0.24-0.54)], respectively. The receiver operating characteristics (ROC) curve analysis revealed that CysC had a significantly higher diagnostic accuracy than eCCl (p < 0.001).

CONCLUSIONS

Our results identify that the sensitivity of serum CysC for detecting AKI is higher than that of serum Cr in a heterogeneous pediatric intensive care unit (PICU) population.

Lead concentration in breast milk of lactating women who were living in Tehran, Iran

It is obvious that lead intake is of concern not for its beneficial/essential effects on metabolism, but rather for its toxic actions, which can be especially damaging to children. The objective of this study was to analyze the concentration of lead in milk of mothers during prolonged lactation. Milk samples from 43 mothers were collected at 2 months postpartum. Lead was analyzed using atomic absorption spectrophotometer. The value of lead in human milk was 23.66±22.43 μg/l. Lead concentration in human milk of mothers was higher than other countries and no significant relationship was found between levels of human milk lead and mother's education, age, parity, height and weight. The concentrations of lead in the milk samples were high, which makes a major public health hazard for the inhabitants, especially neonatal and children, of the industrial locations.

Frequency of shiga toxin-producing genes of Escherichia coli isolated from diarrheic stools of Iranian children by PCR

OBJECTIVE

Shiga toxin-producing E. coli (STEC) is a pathogenic E. coli that may cause hemolytic uremic syndrome (HUS) after diarrheal disease through Shiga toxins. Management of the patients with STEC infection is different from that of other diarrheal diseases due to increase in frequency of HUS after antibiotic administration. Few studies were conducted in Iran and epidemiology of STEC remains obscure; this necessitates examination of stools especially in young children for this bacterium.

METHODS

We determined the frequency of STEC in 947 E. coli strains isolated from diarrheal stools of children less than 14 years in Tehran with conventional culture methods and multiplex-PCR via determining the STX1 and STX2 genes, between October 2008 and September 2009. We also evaluated the association between stool exam findings and presence of STEC.

FINDINGS

Twenty seven (2.8%) of E. coli isolates were positive for STX1 or STX2 genes, most of which occurred in spring (P<0.05). There was no significant association between STEC positivity and stool exam findings. Eighteen out of 27 (66.7%) Shiga toxin positive samples were isolated from males and the rest from females. The most common STX-positive diarrheal samples showed loose consistency (P<0.017).

CONCLUSION

Although the low frequency of STEC in our population indicates that it is not a major problem in our population, STEC should be regarded as an important infection because of its severe consequences. Further studies with greater sample size are needed to confirm our results.

Variation in plasma leptin levels in young Iranian children with cystic fibrosis

INTRODUCTION

Poor weight gain is one of the most important mortality hazards in cystic fibrosis (CF) patients. The mechanisms that may hinder body weight regulation are not completely understood. Leptin and its role in fat mass could be related to control of weight gain in CF patients. As the previous data are conflicting, we aimed to investigate serum leptin level in Iranian CF children compared to a control group.

MATERIAL AND METHODS

Forty-three CF patients aged from 3 to 120 months and 43 age-matched controls were enrolled. Patients were recruited from the outpatient clinic of the Children's Medical Center Hospital. Controls were visited in the general outpatient clinic for an annual check-up. Both groups were divided into three subgroups based on age: 3 to 12 months, 13 to 48 months, and 49 to 120 months. Body mass index (BMI) was calculated for all the participants. Serum leptin levels were measured applying a solid phase enzyme-linked immunosorbent assay (ELISA).

RESULTS

Leptin levels and BMI values were significantly different between patients and controls (p = 0.02, p < 0.001, respectively) but only patients aged 13-48 months had significantly higher levels of leptin than age-matched controls (p = 0.016). Overall male patients' mean leptin level was significantly higher than in female patients (p = 0.032) and male controls (p < 0.001).

CONCLUSIONS

Leptin level in our patients was significantly higher than controls. It seems that leptin levels during infancy are higher than in adult patients. Further studies are required on specific genotypes, gender and age to reveal the probable correlation with BMI and leptin levels in CF patients from different ethnic groups.

Developing a real-time quantitative loop-mediated isothermal amplification assay as a rapid and accurate method for detection of Brucellosis

AIM

The aim of this study was designing a LAMP method for the rapid detection of Brucella and development of a sensitive quantitative-LAMP (Q-LAMP) assay for quantification of brucellosis.

METHODS AND RESULTS

In this study for the LAMP detection of the causative agent of brucellosis, we used specifically designed primers to target the omp25 conserved gene of Brucella spp. The sensitivity of the LAMP method was evaluated by preparing serial tenfold dilution of omp25 gene containing plasmid followed by performing the LAMP reaction. To improve the assay as a quantitative test, LAMP products in the serial dilution were evaluated by Loopamp real-time turbidimeter system and then standard curve was generated by plotting time threshold values against log of copy number. The assay specificity was evaluated using Brucella genomic DNA and a panel containing genomes of 11 gram-positive and gram-negative organisms. The LAMP assay was highly specific and no amplification products were observed from the non-Brucella organisms. The test sensitivity for visual detection of turbidity or fluorescent colour change and also agarose gel electrophoresis was 560 ng and 5·6 ng, respectively. The lower limit of detection was 17 copies of the gene that could be detected in 50 min.

CONCLUSIONS

The results of this study indicated that the LAMP assay is a simple, rapid, sensitive and specific technique for detection of Brucella spp. that may improve diagnostic potential in clinical laboratories.

SIGNIFICANCE AND IMPACT OF THE STUDY

The LAMP assay because of the simplicity and low cost can be preferred to other molecular methods in the diagnosis of infectious diseases.

Is There any Association Between Passive Smoking and Esophagitis in Pediatrics?

OBJECTIVE

Exposure to environmental tobacco smoke (ETS) is one of the major factors of predisposing children to develop several hazardous health problems. We decided to investigate the association between nicotinine, one of the nicotine metabolites and esophagitis in children with gastroesophageal reflux disease (GERD).

METHODS

In a case control study 46 children suffering from esophagitis referred to endoscopy ward were recruited. The control group consisted of 45 healthy children. Urine samples were collected and urinary cotinine level (UCL) measured.

FINDINGS

The mean age of esophagitis and control groups were 5.11±2.93 and 6.72±2.8 respectively. Sixty children were passive smokers; 31 of them had non-smoker parents. In control group, 32 (71.1%) children and in esophagitis group 29 (63%) children had non-smoker parents. The mean value of UCL in patients suffering from esophagitis was significantly higher than those in normal group (P=0.04, 24.98±6.4 ng/ml vs. 15.16 ± 3.9 ng/ml). Considering 50ng/ml as a cutoff point for UCL, it was significantly higher in passive smoker group than in non smoker group (P=0.02). The mean cotinine level differed significantly in esophagitis and control group.

CONCLUSION

Our results indicate the increased risk of developing esophagitis in children with ETS exposure.

Plasma ghrelin levels in children with cystic fibrosis and healthy children

INTRODUCTION

Cystic fibrosis (CF) is a common genetic disorder as a result of mutation in the CF transmembrane conductance regulator gene. Weight loss in CF patients seems to be multifactorial and metabolic factors, inflammation, recurrent infections and poor appetite are possible candidates. Ghrelin affects energy hemostasis by stimulating growth hormone secretion, glucose and lipid metabolism alteration and inhibition of the inflammatory system. Data on the role of ghrelin in energy deficiency in CF patients are sparse and controversial. The study was done to compare the plasma levels of the acylated form of ghrelin in CF patients with healthy participants.

MATERIAL AND METHODS

Thirty cystic fibrosis patients (aged 1-168 months) and thirty healthy matched participants were enrolled in the study. Plasma ghrelin and albumin levels were measured and body mass index (BMI) was calculated as well.

RESULTS

Plasma levels of acylated ghrelin in CF patients were significantly higher than the control group (mean 25-75%: 14.5 vs. 2.7, p = 0.032). Body mass index measurements in CF patients were significantly lower than the control group (p < 0.001). Using regression analysis there was no statistically significant correlation between plasma ghrelin levels and serum albumin, weight, height or BMI values in CF patients and controls.

CONCLUSIONS

The acylated ghrelin levels are increased in CF. So plasma levels of acylated ghrelin could be used as an indicator of food uptake and energy balance in them. Further studies should be established to find out the exact role of factors affecting energy metabolism.

Alteration of renal functional, oxidative stress and inflammatory indices following hepatic ischemia-reperfusion

Liver ischemia/reperfusion (IR) injury is a complex phenomenon that may cause local as well as remote organ injuries. Reactive oxygen species (ROS) along with many pro- and anti- inflammatory cytokines are implicated in the development of organ injury. The renal functional, histological, oxidative stress and inflammatory indices were studied during a short and a longer period of liver IR. Rats were subjected to either sham operation or 90 min partial liver ischemia followed by 4 or 24 h of reperfusion. Serum ALT, AST, ALK and LDH levels, BUN and creatinine, renal MDA level, SOD and catalase activities were evaluated as well as serum IL-6 and IL-10 concentrations along with renal histological evaluation. Ninety minutes liver ischemia /4 h reperfusion caused an increase in BUN and renal MDA levels and a decrease in SOD and catalase activities. It also caused an increase in serum IL-6 and IL-10 levels. 24 h liver reperfusion resulted in a reduction in BUN levels and lower oxidative damages demonstrated by a decrease in renal MDA levels and an increase in renal SOD and catalase activities comparing to 4 h reperfusion group. Evaluations indicated improvement in histology such as less cytoplasmic vacuolation and lower tubular debris. Serum inflammatory indices (IL-6 and IL-10 levels) were also reduced. This study showed that liver IR damage causes renal injury including functional, inflammatory and oxidative status changes. The remote kidney damage was then improved by continuing reperfusion from 4 to 24 h.

Prevalence of intestinal parasites among children referred to Children's Medical Center during 18 years (1991-2008), Tehran, Iran

Epidemiological studies show that parasitic inections are among the most common infections and one of the biggest health problems of the society worldwide. Children at school age have the highest morbidity compared with other ages. Therefore, by treating these children, the disease burden in the total population is reduced. In this study, prevalence of parasitic infection in children referred to Children's Medical Center was compared in different years. In this retrospective cross-sectional study, the subjects were children under 13 years who were referred to Children's Medical Center Laboratory during 18 years (1991-2008) and underwent stool exam by any reason. The specimens were evaluated by different common methods of stool parasitology. In suspected cases, parasites was cultured in specific medium and stained as needed. Required data were obtained from the laboratory files and analysed according to study's purpose. Subjects were 124 366 children. Among them, 0.78% of cases had parasitic infections and 60.54% cases were male. Parasitic infections were related to protozoa in 95.33% cases and intestinal worms in 4.87%. Of them, 50.352% were pathogenic protozoa. The most parasitic infection was Giardia lamblia. Among intestinal worms, the highest prevalence was related to Hymenolepis nana (40.7%). A comparison between the first 10 years and the next 8 years of the study showed that the prevalence of intestinal parasites were 8% and 1% (P < 0.001) and the rate for protozoal infection were 14.9% and 4.3%, respectively (P < 0.001). The prevalence of intestinal parasites was reduced during recent years; however, more attempts should be performed to make it lower.

Pretreatment with pentoxifylline and N-acetylcysteine in liver ischemia reperfusion-induced renal injury

BACKGROUND AND AIMS

Acute hepatic injury causes systematic inflammatory responses which may finally lead to functional disturbances in remote organs. In this study, the effects of an inhibitor of inflammatory cytokines (pentoxifylline, PTX) and a well-known antioxidant, N-acetylcysteine (NAC), were evaluated on renal damage and oxidative stress following liver ischemia reperfusion (IR).

METHOD

Five groups of six male rats were used. Group 1 was sham operated. In group 2, 90 min liver partial ischemia was induced by a clamp around both hepatic artery and portal vein and then followed by 4 h of reperfusion. In groups 3 and 4, PTX or NAC was injected intraperitoneally before the ischemia, while in group 5 both drugs were co-administered. The levels of alanine amino-transferase (ALT), aspartate amino-transferase (AST), blood urea nitrogen (BUN), and creatinine in serum as well as malonyldialdehyde (MDA) and glutathione (GSH) levels and morphological changes in renal tissues were assessed.

RESULTS

Significant increase in the serum levels of ALT and AST in IR group is indicative of liver functional damages. Elevated BUN and renal tissue MDA, decreased GSH levels, and morphological damages in IR group demonstrate a significant kidney injury and oxidative stress comparing to sham group. Administration of PTX alone and PTX + NAC prevented the IR-induced increase in renal MDA levels. Administration of both drugs and their co-administration prevented the reduction in renal GSH levels and morphological changes.

CONCLUSION

Pretreatment with PTX and NAC before liver IR may be useful to ameliorate renal oxidative damage by preservation of cellular GSH concentration and a reduction in MDA levels.

Establishment of a Modified in Vitro Cultivation of Protoscoleces to Adult Echinococcus granulosus; an Important Way for New Investigations on Hydatidosis

BACKGROUND

Echinococcus granulosus, a zoonotic cestode parasite, causative agent of hydatid cyst is endemic in many parts of the world including the Middle East. Study on different aspects of this parasite is very important and valuable. However, working with adult worms which their habitat situated in the small intestine of canids, is dangerous and risky. Achieving such risky situation needs a controlled condition which is cultivation of the organisms in the laboratory. In this regard, cultivation of E. granulosus protoscoleces leading to adult worms was established in the laboratory for the first time in Iran.

METHODS

Under aseptic conditions a number of protoscoleces were cultivated in diphasic S.10E.H medium using CO2 incubator to produce adult worms.

RESULTS

Different forms of parasites including pre-segmentation stages (PS1 - PS4) and segmentation stages (S5-S8) and developing stages in segmented worms (S10-S11) were observed and evaluated in these medium. Finally adult worms contained four proglottids with a large and distinct genital pore were observed 50-55 days post cultivation. These parasites do not produce fertile eggs and conclusively do not have risk of hydatid disease transmission to the researchers.

CONCLUSION

The mentioned method for producing E. granulosus adult worms can open a new window for researches and facilitate working on different aspects of hydatidosis especially for diagnosis, protection and treatment studies.

Total Antioxidant Status in Patients with Major β-Thalassemia

OBJECTIVE

Beta-thalassemia major is an autosomal recessive disease causing severe and hemolytic anemia, which begins about 2-6 months after birth. Iron overload, which arises from recurrent transfusion and ineffective erythropoiesis, can enhance oxidative stress in thalassemic patients. The aim of this study was to evaluate the serum total antioxidant capacity of patients with ß-Thalassemia major.

METHODS

Sixty six Iranian patients with β-thalassemia major and 66 age-gender matched controls were evaluated for serum total antioxidant status (TAS), uric acid (UA), bilirubin and albumin. In addition, serum ferritin and transaminases were recorded in these subjects.

FINDINGS

Significant increases of TAS, UA, and bilirubin were observed in the patient group, compared with the control group (P<0.01). Mean TAS and bilirubin in male patients was higher than in females (P=0.005 and P=0.008, respectively). There was also direct correlation between TAS and albumin (P<0.001), bilirubin (P<0.001) and UA (P=0.002).

CONCLUSION

Endogenous antioxidants such as ferritin, UA and bilirubin can result in increased level of TAS in the patients with Beta-thalassemia major. Compensatory excess of TAS to oxidative stress could also be the reason for difference between our findings and previous studies.

Usefulness of procalcitonin rapid test for the diagnosis of acute pyelonephritis in children in the emergency department

BACKGROUND

Urinary tract infection (UTI) is a common problem in children. The aim of this study was to determine the usefulness of the procalcitonin (PCT) rapid test in the diagnosis of renal involvement in children with urinary tract infection.

METHODS

Through a case series study, PCT and C-reactive protein rapid tests were measured in children with proven UTI at the Tehran Children's Medical Center, Iran. One-hundred patients aged 1 month-14 years old (19 boys and 81 girls) with documented UTI were enrolled in the study.

RESULTS

Of 100 children, 62 patients (62%) had renal involvement on the basis of abnormal Tc-dimercaptosuccinic acid scintigraphy and 38 patients (38%) had infection restricted to the lower urinary tract. There were no differences related to age or gender among the groups. The sensitivity and specificity of PCT were 77% and 89%, respectively, in prediction of renal involvement, whereas C-reactive protein had a sensitivity of 80% and a specificity of 65%.

CONCLUSION

We concluded that a rapid determination of PCT concentration could be useful for the management of children with febrile UTI in the emergency room.

The prevalence of iron deficiency anaemia in female medical students in Tehran

INTRODUCTION

Female adolescents and adults are among the population groups who are most affected by iron deficiency. Thus, the aim of this study was to investigate the prevalence of iron deficiency and iron deficiency anaemia in female students aged 18 to 25 years old from the Tehran University of Medical Sciences, Iran.

METHODS

295 female university students participated in the study. The mean corpuscular volume (MCV) and haemoglobin (Hb), serum ferritin, serum iron and total iron binding capacity (TIBC) levels were measured. Iron deficiency anaemia was defined as a situation where Hb is less than 12 g/dL, MCV is less than 78 microm3, ferritin is less than 12 ng/ml or transferin saturation (TS) (iron/TIBC x 100) is less than 15 percent, Iron deficiency (ID) was defined as a situation where Hb is greater than or equal to 12 g/dL, MCV is greater than or equal to 74 microm3, ferritin is less than 12 ng/ml or TS is less than 15 percent.

RESULTS

The complete data was available for 237 students. The prevalence of ID was 40.9 percent and that of IDA was 3.8 percent. Normal iron status was found in 49.8 percent of the subjects. The remaining (5.5 percent) had other kinds of anaemia or required confirmatory tests.

CONCLUSION

ID is common among 18 to 25-year-old Iranian female university students. Iron supplementation is thus required for the target group.

Vitamin D insufficiency among children and adolescents living in Tehran, Iran

Vitamin D is important for calcium absorption and skeletal growth. Vitamin D insufficiency (VDI) is a prevalent health problem in children. A study was performed to determine the prevalence of VDI in healthy children living in Tehran, Iran. In a cross-sectional study, 963 students (424 boys and 539 girls) aged 7-18 years were selected by random sampling. Serum 25-hydroxyvitamin D (25-OHD), calcium, alkaline phosphatase and phosphorus were measured. VDI was defined as serum 25-OHD <20 ng/ml. Prevalence of VDI was 53.6% in girls and 11.3% in boys. VDI in female students was about five times more common than males (p < 0.000001). VDI in children and adolescent girls is a health problem not only for these age-groups but also for the next generation to come. Encouraging girls to have more sun exposure, fortification of foods and prescription of supplemental vitamin D are recommended.

Adenosine deaminase in patients with primary immunodeficiency syndromes: the analysis of serum ADA1 and ADA2 activities

OBJECTIVES

We aimed to investigate the activity of ADA and its isoenzymes in serum of patients with various primary immunodeficiency (PID) syndromes.

DESIGN AND METHODS

Total ADA (tADA) and its isoenzymes were measured in 76 children with PID syndromes and 30 healthy controls using the Ellis method.

RESULTS

Our results indicated that tADA and ADA2 levels were higher in patients with Chronic Granulomatous Disease (CGD), Leukocyte Adhesion Deficiency (LAD), hyper IgM (HIM) and Wiskott-Aldrich Syndrome (WAS) than those of corresponding controls (P<0.01). There was a significant elevation of tADA and ADA1 activities in IgA deficiency patients as compared to healthy individuals (P<0.01).

CONCLUSIONS

Our results hypothesized that altered ADA activity may be associated with altered immunity. Therefore, serum ADA level could be used as an indicator along with other parameters in follow up of patients with CGD, LAD, IgA deficiency, HIM and WAS.

A Probable Causative Factor for an Old Problem: Selenium and Glutathione Peroxidase Appear to Play Important Roles in Epilepsy Pathogenesis

PURPOSE

Only recently has it become known that oxidative stress and generation of reactive oxygen species are the cause and the consequence of epileptic seizures. Due to the protective role of selenium (Se) and selenoproteins against oxidative damage and the ability to promote neuronal cell survival, we compared serum selenium level and red blood cell Glutathione peroxidase activity (RBC GPx) between epileptic and healthy children.

METHODS

In a case control study, 53 epileptic children were compared with 57 healthy children in the same age and community of residence. Serum Se and RBC GPx activity were measured with an atomic absorption spectrophotometry and Cayman standard glutathione assay kit, respectively.

RESULTS

The mean (+/-standard deviation) of serum Se was 72.90 microg/L (+/-22.20) and 86.00 microg/L (+/-15.00) in patient and control groups, respectively. For RBC GPx activity the mean (+/-standard deviation) was 440.57 nmol/min/ml (+/-264.00) and 801.00 nmol/min/ml (+/-267.00) in patient and control groups, respectively. Statistical analysis showed a significant lower means of serum Se and RBC GPx activity in patient group compared to that of healthy control group (p < 0.001).

CONCLUSION

Lower serum Se and RBC GPx activity in epileptic patients compared to healthy children may support the proposed crucial role of Se and GPx activity in the pathogenesis of epilepsy. However, RBC GPx activity in the case of selenium deficiency could not be a sensitive and specific indicator of Se status in serum that led us to supplant Se measurement with RBC GPx activity.