358 research outputs found

    Extremal Vanishing Horizon Kerr-AdS Black Holes at Ultraspinning Limit

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    By utilizing the ultraspinning limit we generate a new class of extremal vanishing horizon (EVH) black holes in odd dimensions (d5d\geq5). Starting from the general multi-spinning Kerr-AdS metrics, we show the EVH limit commutes with the ultraspinning limit, in which the resulting solutions possess a non-compact but finite area manifold for all (t,rr+)=const.(t,r\neq r_+)=const. slices. We also demonstrate the near horizon geometries of obtained ultraspinning EVH solutions contain an AdS3_3 throats, where it would be a BTZ black hole in the near EVH cases. The commutativity of the ultraspinning and near horizon limits for EVH solutions is confirmed as well. Furthermore, we discuss only the five-dimensional case near the EVH point can be viewed as a super-entropic black hole. We also show that the thermodynamics of the obtained solutions agree with the BTZ black hole. Moreover we investigate the EVH/CFT proposal, demonstrating the entropy of 22d dual CFT and Bekenstein-Hawking entropy are equivalent.Comment: 29 pages, 3 figures, references added, typos corrected, revised version to match published versio

    Group A �-hemolytic streptococcal infection in children and the resultant neuro-psychiatric disorder; a cross sectional study; Tehran, Iran

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    Introduction: Group A Beta-Hemolytic Streptococcus (GABHS) can induce PANDAS (pediatric autoimmune neuropsychiatric disorders associated with streptococcal infection). GABHS is the most important and common bacterial cause of acute pharyngitis in Iranian children. We studied the role of GABHS (anti-streptococcal antibodies) in suspected cases of PANDAS in a cross sectional studies. Methods: Across sectional study was done in 2 pediatric psychiatric/and neurologic clinics in Tehran (Rasul Akram and Aliasghar Hospital) during 2008-2010. We studied serum antistreptococcal antibodies (anti streptolysin O, anti Deoxyribonuclease B, and anti-streptokinase (ABcam-ELISA, USA) in 76 cases with psychiatric manifestation (OCD, ADHD) in compare with 39 healthy controls. These antibodies were studied in 53 cases with movement disorders (Tic/Tourette syndrome) in compare with 76 healthy controls. Sensitivity, specificity and positive predictive value of tests were calculated. Results: In movement disorders ASOT, Anti-DNase and Anti streptokinase was significantly higher than controls (p 200IU/ml) had 75 sensitivity; 84 specificity and 80 PPV; Antistreptokinase (cut off level> 332 IU/ml) had 34 sensitivity; 85 specificity, and 72 PPV; Anti-DNase (cut off level> 140IU/ml) had 70 sensitivity; 99 specificity and PPV 90 for differentiating the group. ASOT, Anti-DNase and Anti streptokinase titer was significantly higher than controls (p<0.0001, p=0.000, p<0.0001). ASOT had 90 sensitivity; 82 specificity, PPV 92; Anti streptokinase: 82 sensitivity; 82 specificity, PPV 95; Anti DNase: 92 sensitivity; 82 specificity, PPV 92 for differentiation the cases from normal controls. Discussion: These findings support that a post infectious immune mechanism to GABHS may play a role in the pathogenesis of PANDAS in our children. A combination of throat culture, rapid antigen detection test, and serologic testing for GABHS is required to achieve maximum sensitivity and specificity for diagnosis. We prefer to use antibiotic prophylaxis in PANDAS cases for preventing recurrent streptococcal infections. Ongoing research is needed for identifying optimum diagnostic, prevention and therapeutic approach especially, aggressive treatment (intravenous immunoglobulin, plasmaphresis)

    Serum levels of vitamins A and D, and zinc in children with acute diarrhea: A cross-sectional study

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    Background: Diarrhea is a leading cause of mortality and morbidity during the early life period especially in developing countries. Micronutrients deficiencies have been proposed either as a risk factor or a consequence of diarrhea. Association studies highlight the relation of vitamins and minerals' deficiencies with acute diarrhea. In this regard we aimed to evaluate the status of vitamins A and D, and zinc serum levels in children with acute diarrhea. Methods: In this cross sectional study performed in a referral teaching hospital, we measured and compared baseline vitamin A, 25-hydroxy vitamin D (25(OH)D), and zinc serum levels in 25 children admitted with acute diarrhea and 25 other children who were admitted for undergoing elective surgeries. Results: 25-(OH)D levels were significantly lower in the diarrhea group (p=0.03). We were unable to demonstrate a significant difference in the levels of vitamin A and zinc between the case and control groups (p= 0.14 and p=0.07, respectively). Conclusion: We observed lower serum 25(OH)D levels in children with acute diarrhea. Whether this finding indicates a premorbid risk factor or simply a consequence of diarrhea needs further studies. Regardless of the cause and effect relationship, supplementation with vitamin D in acute diarrhea remains as a plausible consideration

    Endoscopic screening for precancerous lesions of the esophagus in a high risk area in northern Iran

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    Background: Esophageal squamous cell carcinoma (ESCC) is a major health problem in many developing countries, including Iran. ESCC has a very poor prognosis, largely due to late diagnosis. As a first step in developing an early detection and treatment program, we conducted a population-based endoscopic screening for ESCC and its precursor lesion, esophageal squamous dysplasia (ESD), in asymptomatic adults from Golestan Province, northern Iran (a high-risk area for ESCC) to evaluate the feasibility of such a program and to document the prevalence and risk factor correlates of ESD. Methods: This cross-sectional study was conducted among participants of the Golestan Cohort Study (GCS), a population-based cohort of 50,000 adults in eastern Golestan Province. Randomly selected GCS participants were invited by telephone. Those who accepted were referred to a central endoscopy clinic. Eligible subjects who consented were asked to complete a brief questionnaire. Detailed information about selected risk factors was obtained from the GCS main database. Endoscopic examination with was performed with Lugol's iodine staining; biopsies were taken from unstained lesions as well as the normally stained mucosa of the esophagus, and the biopsies were diagnosed by expert pathologists according to previously described criteria. Results: In total, 1906 GCS subjects were invited, of whom only 302 (15.8%) were successfully enrolled. Esophagitis (29.5%) and ESD (6.0%) were the most common pathological diagnoses. Turkmen ethnicity (adjusted OR = 8.61; 95%CI: 2.48-29.83), being older than the median age (OR = 7.7; 95% CI: 1.99-29.87), and using deep frying cooking methods (OR = 4.65; 95%CI: 1.19-18.22) were the strongest predictors for ESD. There were significant relationships between esophagitis and smoking (p-value<0.001), drinking hot tea (P value = 0.02) and lack of education (P value = 0.004). Conclusion: We observed a low rate of participation in endoscopic screening. The overall prevalence of ESD was 6.0%. Developing non-endoscopic primary screening methods and screening individuals with one or more risk factors may improve these rates

    Evaluation of fluconazole effect in prevention of fungal infection and mortality and morbidity in very low-birth-weight infants

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    Background: Fungal infections especially Candida species are frequent cause of mortality and morbidity in very low-birth-weight (VLBW) infants receiving intensive care; Candida infections are tissue invasive. This infection increases the risks of adverse neurodevelopmental sequelae. Prevention and treatment of fungal infection is so important in very VLBW infants. The aim of this study was to determine the prophylactic effect of fluconazole in decreasing the mortality and morbidity in VLBW infants (less than 1500gr) admitted in NICU. Methods: This prospective case control study were conducted among 102 Infants (weighing less than 1500gr at birth at born) admitted in NICU department of Ali Asghar University Hospital from 2012 to 2013, Tehran, Iran. Weigh of birth in cases and groups were less than 1500 gr and both were culture negative. Cases received oral fluconazole 3 mg/kg in 3 days in 1st and 2nd weeks, alternate day in 3rd and 4th weeks, daily in 5th and 6th weeks. Control groups had not received fluconazole. Mortality and morbidity and hospital stay were compared between cases and controls groups. Results: We studied 49 very low-birth-weight infants with negative culture as cases (received fluconazole prophylaxis), 46 VLBW infants without fluconazole profilaxy (controls). No significant difference in gestational age (P=0.2), and mean weights (P=0.4) were observed between cases and controls. The mortality rate 8.7 (n=4) in controls (without prophylactic fluconazole) observed vs 2 (n=1) mortality rate in VLBW cases (with prophylactic fluconazole). Although the mortality rate in controls was 4 times higher than cases, but without significant differences (P=0.1). Indeed, mean duration of hospital stay in controls was longer than cases (28.41±9.93 vs 19.85±6.19 days, P=0.00001). Conclusion: Although prophylactic fluconazole in VLBW could decrease the mortality of cases (control the fungal infection) 4 fold in compare with controls (no treatment), it was not significant. The prophylactic effect of fluconazole might decrease the length of hospital stay of VLBW neonates in NICU. Due to limited number of cases and control. For further decision about prophylactic use of fluconazole, prospective RCT studies with larger cases and control would be helpful in future. © 2016, Tehran University of Medical Sciences. All rights reserved

    Cerebrospinal fluid lead level in patients with idiopathic seizure

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    Background: Convulsion is one of the common cause of hospital admission in children. Idiopathic seizure is when no anatomic, electrolytic, metabolic or hemorrhagic causes are found. Recently, lead poisoning, which is considered when serum lead levels are higher than the normal levels (previously 10 µg/dl changed to 5 µg/dl). Even lower levels of lead inflict harmful consequences in central nervous system (CNS) development in pediatric group. Due to air pollution and high lead level in air of Tehran, investigation the probable role of lead in producing or predisposing convulsion in children is very important. To determine the cerebrospinal fluid (CSF) lead level in children with idiopathic convulsion in compare with nonconvulsive ones (control). Methods: A case-control study upon 60 children (30 convulsive and 30 nonconvulsive control) admitted in Rasoul Akram and Ali Asghar University Hospitals, Tehran, from 2012 to 2013 had done. One ml of CSF obtained and lead level determined by atomic absorption test. Results: The mean age between cases and controls was not different (mean= 30.18+27.36 vs 25.46±20.56 months, P= 0.1). The CSF lead level (µg/dl) had not meaningful difference between 2 groups (3.43+3.07 vs 2.78+2.77, P= 0.3), and no related to type of convulsion in cases (P= 0.7), the area under the curve (AUC) was 0.588; 1-0.433, P= 0.2). The CSF lead cutoff was 1.65 µg/dl; sensitivity of 70, specificity of 46, PPV and NPV was 56 and 60 respectively. Conclusion: The toxic blood level for lead is 3.5 µg/dl. The CSF lead level; even in little amount (1.65 µg/dl) is an acceptable sensitivity but lower specificity for differentiation the convulsive from nonconvulsive children. Although the role of genetic and other causes should be considered in idiopathic convulsion, probably, the high level of lead in CSF could predispose those children to convulsion. It can effect CNS development in children even in small amounts. Indeed, long-term effects of lead which continue to adulthood should be considered as well. Hence, it is paramount to rectify the ambient air lead pollution in Tehran. © 2015 Tehran University of Medical Sciences. All rights reserved
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