JAK Inhibitor Therapy in a Child with Inherited USP18 Deficiency.

Deficiency of ubiquitin-specific peptidase 18 (USP18) is a severe type I interferonopathy. USP18 down-regulates type I interferon signaling by blocking the access of Janus-associated kinase 1 (JAK1) to the type I interferon receptor. The absence of USP18 results in unmitigated interferon-mediated inflammation and is lethal during the perinatal period. We describe a neonate who presented with hydrocephalus, necrotizing cellulitis, systemic inflammation, and respiratory failure. Exome sequencing identified a homozygous mutation at an essential splice site on USP18. The encoded protein was expressed but devoid of negative regulatory ability. Treatment with ruxolitinib was followed by a prompt and sustained recovery. (Funded by King Saud University and others.).

Glassy Carbon Electrode Electromodification in the Presence of Organic Monomers: Electropolymerization versus Activation.

Several reports in the literature deal with the modification of glassy carbon electrode (GCE) surface via electropolymerization of some organic monomers, particularly p-aminobenzenesulfonic acid (p-ABSA) and l-cysteine using intensive oxidative conditions, and attributed the improved electrocatalytic activities toward various analytes to the formation of the electropolymerized layer. What is the real cause for this improvement in electrocatalytic activity? Is it because of the electrochemical activation process of GCE or electropolymerization? Combining a set of surface and electrochemical characterization techniques, we first showed that the electrochemical peaks previously assigned in many reports to electropolymerization processes at the surface of GCE correspond to electrochemical activation of the GCE surface. We further demonstrated that the anodization of GCE at high voltage causes activation of its surface and the formation of surface functional groups (SFGs). In fact, those SFGs are found to be the main reason for the enhancement in electrocatalytic activity of the activated GCE (AGCE). The surface features of the modified electrodes were characterized by Raman spectroscopy, attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX). The electrochemical behavior was investigated using cyclic voltammetry (CV). The analytical performance of AGCE toward dopamine (DA) was assessed using differential pulse voltammetry (DPV). As compared to the previously reported dopamine electrochemical sensors assuming such electropolymerization processes, the AGCE showed analytical performance practically similar to that of these sensors. This further confirms that the enhancement in electrocatalytic activity is due to the electrochemical activation of the GCE surface.

Pediatric intracranial hypertension. Experience from 2 Tertiary Centers.

OBJECTIVE: To review the experience of 2 tertiary centers in Saudi Arabia with intracranial hypertension (IH) in the pediatric population. METHODS: We retrospectively reviewed and analyzed pediatric patients diagnosed with IH from June 2002 to May 2017 in 2 institutes. RESULTS: We identified 53 patients (30 females and 23 males) with a mean age of 7 years at the time of presentation. Among them, 41 patients were younger than 12 years, and 12 were older. Obese and overweight patients constituted 27.00% (n = 14) of all cases, 8 (66.7%) of whom were older than 12 years. The most common presenting feature was papilledema followed by headache. Vitamin D deficiency, which constituted the most common associated condition, was identified in 12 (22.6%) patients. Acetazolamide was the treatment option in 98.11% of patients, and only 5.7% underwent surgical interventions. The length of follow-up ranged from 6 months to 8 years. CONCLUSION: Intracranial hypertension is rare in children and commonly seen in overweight females older than 12 years similar to adults. Patients younger than 12 years tend to develop secondary IH. More studies are needed to characterize the clinical presentation and guide the management plan.

A newly recognized autosomal recessive syndrome affecting neurologic function and vision.

Genetic factors represent an important etiologic group in the causation of intellectual disability. We describe a Saudi Arabian family with closley related parents in which four of six children were affected by a congenital cognitive disturbance. The four individuals (aged 18, 16, 13, and 2 years when last examined) had motor and cognitive delay with seizures in early childhood, and three of the four (sparing only the youngest child) had progressive, severe cognitive decline with spasticity. Two affected children had ocular malformations, and the three older children had progressive visual loss. The youngest had normal globes with good functional vision when last examined but exhibited the oculodigital sign, which may signify a subclinical visual deficit. A potentially deleterious nucleotide change (c.1A>G; p.Met1Val) in the C12orf57 gene was homozygous in all affected individuals, heterozygous in the parents, and absent in an unaffected sibling and >350 normal individuals. This gene has no known function. This family manifests a autosomal recessive syndrome with some phenotypic variability that includes abnormal development of brain and eyes, delayed cognitive and motor milestones, seizures, and a severe cognitive and visual decline that is associated with a homozygous variant in a newly identified gene.

Novel preparation of metal-free carbon xerogels under acidic conditions and their performance as high-energy density supercapacitor electrodes.

The development of metal-free supercapacitor electrodes with a high energy density is a crucial requirement in the global shift towards sustainable energy sources and industrial pursuit of an optimal supercapacitor. Indeed, from an industrial perspective, time assumes a paramount role in the manufacturing process. A majority of synthesis methods employed for the fabrication of carbon xerogel-based supercapacitor electrodes are characterized by prolonged durations, and result in relatively poor energy and power density. These limitations hinder their practical applications and impede their widespread manufacturing capabilities. In this study, carbon xerogel-based supercapacitor electrodes were made in the shortest time ever reported by making the condition highly acidic with hydrochloric acid (HCl). Furthermore, the investigation of the effect of HCl concentrations (0.1 M, 0.05 M, and 0.01 M) on the morphology and electrochemical behavior of the prepared samples is reported herein. Interestingly, the highest concentration of HCl developed the highest BET surface area, 1032 m2 g-1, which enforced the capacitive behavior to deliver a specific capacitance of 402 F g-1 at 1 A g-1 and a capacitance retention of 80.8% at a current density of 2 A g-1 in an electrolyte containing 0.5 M H2SO4 + 0.5 M Na2SO4. Moreover, an impressive energy density of 45 W h kg-1 at a power density of 18.2 kW kg-1 was achieved. Interestingly, as the HCl concentration increased, the equivalent series resistance decreased to 3.9 W with carbon xerogel 0.1 M HCl (CX0.1). The superior performance of CX0.1 may be attributed to its enlarged BET surface area, pore volume, pore diameter, and smaller particle size. This work provides a facile approach for the large-scale production of metal-free carbon supercapacitor electrodes with improved performance and stability and opens novel horizons to explore the impacts of many types of catalysts during the carbon xerogel preparation.

Activated Glassy Carbon Electrode as an Electrochemical Sensing Platform for the Determination of 4-Nitrophenol and Dopamine in Real Samples.

Glassy carbon electrode (GCE) was electrochemically activated using a repetitive cyclic voltammetric technique to develop an activated glassy carbon electrode (AGCE). The developed AGCE was optimized and utilized for the electrochemical assay of 4-nitrophenol (4-NP) and dopamine (DA). Cyclic voltammetry (CV) was employed to investigate the electrochemical behavior of the AGCE. Compared to the bare GCE, the developed AGCE exhibits a significant increase in redox peak currents of 4-NP and DA, which indicates that the AGCE significantly improves the electrocatalytic reduction of 4-NP and oxidation of DA. The electrochemical signature of the activation process could be directly associated with the formation of oxygen-containing surface functional groups (OxSFGs), which are the main reason for the improved electron transfer ability and the enhancement of the electrocatalytic activity of the AGCE. The effects of various parameters on the voltammetric responses of the AGCE toward 4-NP and DA were studied and optimized, including the pH, scan rate, and accumulation time. Differential pulse voltammetry (DPV) was also utilized to investigate the analytical performance of the AGCE sensing platform. The optimized AGCE exhibited linear responses over the concentration ranges of 0.04-65 µM and 65-370 µM toward 4-NP with a lower limit of detection (LOD) of 0.02 µM (S/N = 3). Additionally, the AGCE exhibited a linear responses over the concentration ranges of 0.02-1.0 and 1.0-100 µM toward DA with a lower limit of detection (LOD) of 0.01 µM (S/N = 3). Moreover, the developed AGCE-based 4-NP and DA sensors are distinguished by their high sensitivity, excellent selectivity, and repeatability. The developed sensors were successfully applied for the determination of 4-NP and DA in real samples with satisfactory recovery results.

Tailoring the Oxygen Reduction Activity of Hemoglobin through Immobilization within Microporous Organic Polymer-Graphene Composite.

A facile one-pot, bottom-up approach to construct composite materials of graphene and a pyrimidine-based porous-organic polymer (PyPOP), as host for immobilizing human hemoglobin (Hb) biofunctional molecules, is reported. The graphene was selected because of its excellent electrical conductivity, while the PyPOP was utilized because of its pronounced permanent microporosity and chemical functionality. This approach enabled enclathration of the hemoglobin within the microporous composite through a ship-in-a-bottle process, where the composite of the PyPOP@G was constructed from its molecular precursors, under mild reaction conditions. The composite-enclathrated Fe-protoporphyrin-IX demonstrated electrocatalytic activity toward oxygen reduction, as a functional metallocomplex, yet with a distinct microenvironment provided by the globin protein. This approach delineates a pathway for platform microporous functional solids, where fine-tuning of functionality is facilitated by judicious choice of the active host molecules or complexes, targeting specific application.

Stroke from cervicocephalic arterial dissection in Saudi children.

Cervicocephalic arterial dissection CCAD is an important, but rarely recognized, cause of stroke in children. We describe 3 cases of CCAD who were diagnosed during a study on childhood stroke which included 104 patients. A high index of suspicion and targeted investigations are needed for the diagnosis and management of CCAD in childhood.

Stroke from systemic vascular disorders in Saudi children. The devastating role of hypernatremic dehydration.

Systemic vascular disorders, leading to childhood stroke, include volume depletion or systemic hypotension and hypernatremic dehydration. We describe 3 cases of stroke following systemic vascular disorders. These were diagnosed during a prospective and retrospective study on childhood stroke, which included 104 patients. Post-gastroenteritis hypernatremic dehydration is an important, potentially preventable, cause of stroke in Saudi children.

Perinatal stroke in Saudi children. Clinical features and risk factors.

OBJECTIVES: To describe the clinical features and presentations of perinatal stroke in a prospective and retrospective cohort of Saudi children and ascertain the risk factors. METHODS: Patients with perinatal stroke were identified from within a cohort of 104 Saudi children who were evaluated at the Division of Pediatric Neurology at King Khalid University Hospital, College of Medicine, King Saud University, Riyadh, Saudi Arabia from July 1992 to February 2001 (retrospective study) and February 2001 to March 2003 (prospective study). Neuroimaging for suspected cases of stroke consisted of cranial CT, MRI, or both. RESULTS: During the study period, 23 (22%) of 104 children (aged one month to 12 years) were diagnosed to have had perinatal stroke. The male:female ratio was 1.6:1. Ten (67%) of the 15 children who had unilateral ischemic involvement had their lesion in the left hemisphere. The presentation of the ischemic result was within 24-72 hours of life in 13 (57%) patients, and in 6 children (26%), motor impairment was recognized at or after the age of 4 months. Nine children (39%) had seizures at presentation. Pregnancy, labour, and delivery risk factors were ascertained in 18 (78%) cases. The most common of these included emergency cesarean section in 5 cases, and instrumental delivery in another 5. Screening for prothrombotic risk factors detected abnormalities in 6 (26%) patients on at least one test carried out between 2 months and 9 years of age. Four children (17%) had low protein C, which was associated with low protein S and raised anticardiolipin antibodies (ACA) in one patient, and low antithrombin III in another. Low protein S was detected in a 42-month-old boy. The abnormality in the sixth child was confined to raised ACA. CONCLUSIONS: The present study highlights the non-specific features by which stroke presents during the neonatal period. The data are in keeping with the potential role for inherited and acquired thrombophilia as being the underlying cause. However, the high prevalence of additional acquired antenatal and perinatal risk factors support a multifactorial disorder.

Infectious and inflammatory disorders of the circulatory system as risk factors for stroke in Saudi children.

OBJECTIVE: To report on the role of infectious and inflammatory disorders as risk factors for stroke in a prospective and retrospective cohort of Saudi children. METHODS: Children, who presented with stroke, were evaluated at the Division of Pediatric Neurology or admitted to King Khalid University Hospital, College of Medicine, King Saud University, Riyadh, Kingdom of Saudi Arabia during the periods July 1992 to February 2001 (retrospective study) and February 2001 to March 2003 (prospective study). Investigations for suspected cases included hemostatic assays, microbiological and serological tests. Neuroimaging included cranial CT, MRI, magnetic resonance angiography (MRA), magnetic resonance venography (MRV) and single photon emission computed tomography (SPECT) brain scan. RESULTS: Of the 104 Saudi children with stroke, seen during the combined study periods of 10 years and 7 months, infectious and inflammatory disorders of the circulatory system were the identified risk factor in 18 (17.3%). Five children had stroke following acute bacterial meningitis at ages ranging between 5-21 months. The causative organism was identified in 3 of them and consisted of Haemophilus influenzae (in a 5-month-old girl), Streptococcus pneumoniae (in a 21-month-old girl complicated by subdural empyema and sinovenous thrombosis), and Staphylococcus aureus in a 6-month-old boy who had an underlying chronic granulomatous disease. Unspecified meningitis/meningoencephalitis affected 4 patients, whereas 3 children had an underlying congenital infection as a cause for their stroke. Two of the latter 3 children were diagnosed to have congenital toxoplasmosis, and the third had congenital rubella syndrome. Two girls had stroke following septicemia at ages of one and 2 months. Neurobrucellosis caused stroke in 2 boys at the ages of 4 1/2 and 4 years. In both patients, neuroimaging revealed lacunar and other infarcts involving mainly the deep cerebral nuclei, secondary to occlusion of small penetrating end arteries. Two patients presented with cerebrovascular disease following systemic lupus erythematosus. These were a 12-year-old girl and a 5-year-old boy. CONCLUSIONS: Several of the infectious diseases that caused stroke in this cohort of Saudi children are potentially preventable through childhood immunization programs or other maternity health programs. In particular, immunogenic conjugate vaccines against the 3 most common organisms causing acute bacterial meningitis (Haemophilus influenzae type b, Neisseria meningitidis and defined serotypes of Streptococcus pneumoniae) are needed to protect the young (<2 years) who are mostly affected.

Stroke due to mitochondrial disorders in Saudi children.

OBJECTIVE: To report on the clinical and biochemical features of patients who presented with stroke due to mitochondrial disorders amongst a prospective and retrospective cohort of Saudi children. METHODS: Children, who presented with stroke, were evaluated at the Division of Pediatric Neurology, or admitted to King Khalid University Hospital, College of Medicine, King Saud University, Riyadh, Kingdom of Saudi Arabia, during the periods July 1992 to February 2001 (retrospective study) and February 2001 to March 2003 (prospective study). Open muscle biopsies were obtained from patients suspected to have mitochondrial disorders, and examined using conventional histological and histochemical techniques. Biochemical, molecular pathological investigations, or both, of muscle could be arranged for only some of the patients. RESULTS: Mitochondrial disorders were the underlying risk factor for stroke in 4 (3.8%) of 104 children (aged one month to 12 years). Three patients (one male and 2 females) had Leigh syndrome (LS) and one had mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes (MELAS). At the time of stroke, the 3 children with LS were 11 months, 15 months, and 7 years old. They presented with psychomotor regression and seizures. Muscle histology and histochemistry showed mild non-specific changes but no ragged red fibers. Biochemical analysis of muscle (in one patient) revealed deficiency of pyruvate dehydrogenase complex. Analysis of mitochondrial DNA (mtDNA), [the other 2 patients] was negative for the 2 point mutations (T-G and T-C) at nucleotide position 8993, and for two T-C point mutations (at positions 8851 and 9176 of the ATPase 6 gene) that have been described in patients with LS. The girl with MELAS syndrome presented with a stroke-like episode at the age of 29 months and had focal brain lesions in the medial aspect of the left occipital and temporal lobes, and in the posteromedial aspect of the left thalamus, which resolved within 7 weeks. She had raised cerebrospinal fluid lactate but no ragged red fibers on muscle histochemistry. Biochemical assay of muscle homogenate showed reduction in respiratory chain complexes I, III and IV. Mutation screening of mtDNA at nucleotides 3243 (tRNA(Leu(UUR))) and 8344 (tRNA(Lys)) was negative. CONCLUSIONS: Mitochondrial disorders constitute a risk factor for stroke in Saudi children. However, demanding and highly specialized investigations are needed to confirm the diagnosis. These are better performed at supraregional centers where facilities for clinical, biochemical and molecular work-up are available.

Congenital and genetic cerebrovascular anomalies as risk factors for stroke in Saudi children.

OBJECTIVE: To explore the role of and report on congenital and genetic cerebrovascular anomalies as risk factors for stroke in a prospective and retrospective cohort of Saudi children. METHODS: Children with stroke were evaluated at the Division of Pediatric Neurology (DPN), or were seen as inpatients in the Pediatric Wards at King Khalid University Hospital (KKUH), Riyadh, Kingdom of Saudi Arabia during the periods July 1992 to February 2001 (retrospective study) and February 2001 to March 2003 (prospective study). Stroke work-up for each suspected case included hemostatic assays, serological, biochemical and neurophysiological tests. Neuroimaging modalities included routine skull x-rays, CT, MRI, magnetic resonance angiography (MRA) and conventional cerebral angiography. RESULTS: Of 104 children with stroke, congenital and genetic cerebrovascular anomalies were the underlying risk factor in 7 (6.7%). The patients were evaluated at the DPN at a mean age of 66 months (range = 8 months to 11 years, median = 6 years); and they had stroke at a mean age of 48 months (range = 2 months to 10 years, median = 8 months). Four patients had stroke in association with neurocutaneous syndromes. Two had Sturge-Weber syndrome (SWS), one had Klippel-Trenaunay syndrome associated with SWS, and the fourth had neurofibromatosis type 1. Two patients had intracranial hemorrhage secondary to ruptured aneurysm. A girl (aged 9 years and 4 months) had left posterior cerebral artery aneurysm. She was diagnosed to have autosomal dominant polycystic kidney disease following renal ultrasonography. She died 5 months later despite surgical intervention (clipping of aneurysm). The second child was an 8-month-old boy who presented with subarachnoid and intraventricular hemorrhage (IVH) following ruptured anterior communicating artery aneurysm. He recovered with no residual symptoms following successful clipping of the aneurysm. Arteriovenous malformation (AVM) caused IVH in a 7-year-old boy who reported to hospital 5 hours after onset of headache, vomiting, drowsiness, and dizziness. Following drainage of the IVH and stabilization of the patient, the AVM was successfully embolized 6 weeks later. CONCLUSIONS: As a group, congenital and genetic cerebrovascular anomalies constitute a significant risk factor for stroke in Saudi children. Recognition of these diseases is important since some are treatable and because other family members may be at risk.

Cardiac diseases as a risk factor for stroke in Saudi children.

OBJECTIVE: To ascertain the role of cardiac diseases as a risk factor for stroke in a cohort of Saudi children who were evaluated in a retrospective and prospective study. METHODS: Children with cardiac diseases were identified from within a cohort of 104 Saudi children who presented with stroke. They were seen as inpatients in the Pediatric Wards or evaluated at the Outpatient Clinics of the Division of Pediatric Neurology (DPN), and the Division of Pediatric Cardiology at King Khalid University Hospital, Riyadh, Kingdom of Saudi Arabia during the periods July 1992 to February 2001 (retrospective study) and February 2001 to March 2003 (prospective study). A comprehensive form for clinical, neuroimaging, neurophysiological and laboratory data retrieval was designed and completed for each patient. Cardiac evaluation included 12-lead ECG and serial echocardiograms. Cardiac catheterization and 24-hour ambulatory ECG (Holter) were conducted on clinical discretion. RESULTS: Cardiac diseases were the underlying risk factor for stroke in 6 (5.8%) of the 104 children (aged one month to 12 years). The patients (4 males and 2 females) were evaluated at the DPN at a mean age of 5.3 years (range = 1-8 years; median 6.5 years). Onset of stroke was at a mean age of 34 months (range = 4 months-8 years; median = 30 months). Five patients had stroke in association with congenital heart disease (CHD), whereas the sixth had restrictive cardiomyopathy. The identified CHD consisted of membranous ventricular septal defect in a 5-year-old boy who had moyamoya syndrome and sickle cell beta(0)-thalassemia, asymptomatic patent ductus arteriosus (PDA) in a 17-month-old girl, atrioventricular canal defect and PDA in an 8-year-old boy who also had Down syndrome, partial anomalous pulmonary venous drainage in a one-year-old boy, and Tetralogy of Fallot in an 8-year-old boy. The latter patient developed hemiparesis secondary to a septic embolus, which evolved into brain abscess involving the right fronto-parietal region. This was successfully managed surgically. The sixth patient was an 8 1/2-year-old girl who had hemiparesis and complex partial seizure in association with restrictive cardiomyopathy. Serial echocardiograms depicted resolution of the cardiac abnormalities within 5 years and subsequent normal findings. CONCLUSIONS: Cardiac diseases, as a group, constitute a significant risk factor for stroke in Saudi children. Early diagnosis of these diseases is important to prevent further recurrences of stroke, and because some of them are potentially curable.

Stroke in Saudi children. Epidemiology, clinical features and risk factors.

OBJECTIVES: To describe the epidemiology and clinical features of stroke in a prospective and retrospective cohort of Saudi children and ascertain the causes, pathogenesis, and risk factors. METHODS: The Retrospective Study Group (RSG) included children with stroke who were evaluated at the Division of Pediatric Neurology, or admitted to King Khalid University Hospital, College of Medicine, King Saud University, Riyadh, Kingdom of Saudi Arabia during the period July 1992 to February 2001. The Prospective Study Group (PSG) included those seen between February 2001 and March 2003. RESULTS: During the combined study periods of 10 years and 7 months, 117 children (61 males and 56 females, aged one month-12 years) were evaluated; the majority (89%) of these were Saudis. The calculated annual hospital frequency rate of stroke was 27.1/100,000 of the pediatric (1 month-12 years) population. The mean age at onset of the initial stroke in the 104 Saudi children was 27.1 months (SD = 39.3 months) and median was 6 months. Ischemic strokes accounted for the majority of cases (76%). Large-vessel infarcts (LVI, 51.9%) were more common than small-vessel lacunar lesions (SVLL, 19.2%). Five patients (4.8%) had combined LVI and SVLL. Intracranial hemorrhage was less common (18.2%), whereas sinovenous thrombosis was diagnosed in 6 (5.8%) patients. A major risk factor was identified in 94 of 104 (89.4%) Saudi children. Significantly more hematologic disorders and coagulopathies were identified in the PSG compared to the RSG (p=0.001), reflecting a better yield following introduction of more comprehensive hematologic and coagulation laboratory tests during the prospective study period. Hematologic disorders were the most common risk factor (46.2%), presumed perinatal ischemic cerebral injury was a risk factor in 23 children (22.1%) and infectious and inflammatory disorders of the circulatory system in 18 (17.3%). Congenital and genetic cerebrovascular anomalies were the underlying cause in 7 patients (6.7%) and cardiac diseases in 6 (5.8%). Six patients (5.8%) had moyamoya syndrome, which was associated with another disease in all of them. Inherited metabolic disorders (3.8%) included 3 children with Leigh syndrome and a 29-month-old girl with mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes. Systemic vascular disease was a risk factor in 3 children (2.9%) including 2 who had hypernatremic dehydration; and post-traumatic arterial dissection was causative in 3 cases (2.9%). Several patients had multiple risk factors, whereas no risk factor could be identified in 11 (10.6%). CONCLUSION: Due to the high prevalence and importance of multiple risk factors, a comprehensive investigation, including hematologic, neuroimaging and metabolic studies should be considered in every child with stroke.

Hematologic risk factors for stroke in Saudi children.

OBJECTIVE: To explore the hematologic risk factors for stroke in a cohort of Saudi children. METHODS: We evaluated children at the Division of Pediatric Neurology at King Khalid University Hospital, College of Medicine, King Saud University, Riyadh, during the periods July 1992 to February 2001 (retrospective study) and February 2001 to March 2003 (prospective study). Investigations for suspected cases included neuroimaging, transcranial Doppler (TCD) for cases of sickle cell disease (SCD), and Duplex scan. Hemostatic assays included coagulation screening tests, tests of thrombin generation and fibrinolysis, coagulation inhibitors, and activated protein C resistance. RESULTS: During the study period, 104 Saudi children (aged one month to 12 years) with stroke were seen. The mean age of the cohort was 27.1 months (SD = 39.3 months) and median was 6 months. Ischemic strokes accounted for the majority of cases (76%). A major risk factor was identified in 93 of 104 cases of stroke (89.4%). Hematologic disorders were the most common (46.2%), followed by prothrombic disorders (31.7%); microcytic hypochromic anemia (26%); sickle cell disease (SCD), or SCbeta(0)-thalassemia, (11.5%), and factor IX deficiency (2.9%). Raised anticardiolipin antibodies (13/49, 26.5%) was the most frequent abnormality. Deficiencies of the natural anticoagulants (protein S, protein C and antithrombin III) were as follows: protein S (15/70, 21.4%); protein C (15/70, 21.4%) and combined deficiency of 2 or more inhibitors (9/70, 12.9%). Activated protein C resistance has not been detected. Contrary to the findings of previous studies from Saudi Arabia, SCD is a common risk factor and is severe, as it resulted in multiple strokes. Moyamoya syndrome was diagnosed in 2 patients with SCD, one of whom had revascularization surgery (encephaloduroarteriosynangiosis). Assessment of children with SCD at risk of stroke was helped by the introduction of TCD followed by neuroimaging, using MRI and magnetic resonance angiography. CONCLUSIONS: The study strongly highlights the importance of prothrombotic disorders and the severe phenotype of SCD as risk factors for stroke in Saudi children.

Moyamoya syndrome as a risk factor for stroke in Saudi children. Novel and usual associations.

OBJECTIVE: To report on moyamoya syndrome (MMS) as a risk factor for stroke in a prospective and retrospective cohort of Saudi children. The usual and novel associations of MMS in this cohort will also be described. METHODS: Children with stroke were evaluated at the Division of Pediatric Neurology at King Khalid University Hospital, College of Medicine, King Saud University, Riyadh, Kingdom of Saudi Arabia during the periods July 1992 to February 2001 (retrospective study) and February 2001 to March 2003 (prospective study). Investigations for suspected cases included hemostatic assays, biochemical, and serological tests. Neuroimaging included CT, MRI, magnetic resonance angiography (MRA), single photon computerized tomography (SPECT) brain scan and conventional cerebral angiography. RESULTS: Moyamoya syndrome was the underlying risk factor for stroke in 6 (5.8%) of the 104 children (aged one month to 12 years). They were 4 females and 2 males. Their first cerebral ischemic event occurred at a mean age of 45 months (median = 44 months, range 17-66 months). In all 6 cases, MMS was associated with an underlying hematologic abnormality or other diseases. Protein C deficiency was identified in one girl and protein S deficiency in another. Two patients had respectively, sickle cell disease (SCD) and sickle cell-beta-thalassemia (S beta-thalassemia), which had been associated in the latter with membranous ventricular septal defect. Adams-Oliver syndrome (AOS, OMIM 100300) was associated with MMS in an 18-month-old girl. A 4-year-old boy had wrinkly skin syndrome (WSS, OMIM 278250) phenotype. The association of MMS and protein C deficiency was first reported in this cohort of patients, whereas the association of the syndrome with WWS and AOS has not, hitherto, been described. The 3 patients who had MMS associated with protein C deficiency, SCD, and AOS underwent successful revascularization surgery in the form of encephaloduroarteriosynangiosis. CONCLUSIONS: Moyamoya syndrome constitutes an important risk factor of stroke in Saudi children. Comprehensive clinical evaluation and investigations, including screening for thrombophilia and neuroimaging studies, are required for the primary diagnosis of the disease and for unraveling other diseases associated with MMS. This will help in managing these patients and in guiding genetic counseling for their families.

Fluid-fluid level in Langerhans cell histiocytosis of the skull.

We present a case of solitary eosinophilic granuloma in the skull of a 6-year-old Saudi boy. This osteolytic lesion has fluid-fluid level on CT and MRI. We are presenting a rare radiological finding of eosinophilic granuloma.

Surface functionality and electrochemical investigations of a graphitic electrode as a candidate for alkaline energy conversion and storage devices.

Graphite is a typical electrocatalyst support in alkaline energy conversion and storage devices such as fuel cells, supercapacitores and lithium ion batteries. The electrochemical behaviour of a graphite electrode in 0.5 M NaOH was studied to elucidate its surface structure/electrochemical activity relationship. Graphite voltammograms are characterized by an anodic shoulder AI and a cathodic peak CI in addition to the oxygen reduction reaction plateaus, PI and PII. AI and CI were attributed to oxidation and reduction of some graphite surface function groups, respectively. Rotating ring disk electrode (RRDE) study revealed two different oxygen types assigned as inner and outer oxygen. The inner oxygen was reduced via the more efficient 4-electron pathway. The outer oxygen reduction proceeded with a lower efficient 2-electron pathway. The calculated percentages of the 4-electron pathway were ranged from 70% to 90%. A full mechanism for the graphite surface function groups changes over the studied potential window was suggested through the combination between the voltammetric, FT-IR and Raman results.