Comparing febrile children presenting on and off antibiotics to the emergency department: a retrospective cohort study.

BACKGROUND: It is not yet known how antibiotics may affect Serious Bacterial Infections (SBI). Our aim is to describe the presentation, management, and serious bacterial infections (SBI) of febrile children on or off antibiotics. METHODS: Retrospective, cohort study of febrile Emergency Department patients, 0-36 months of age, at a single institution, between 2009and 2012. RESULTS: Seven hundred fifty-three patients were included: 584 in the No-Antibiotics group and 169 (22%) in the Antibiotics group. Age and abnormal lung sounds were predictors for being on antibiotics (OR 2.00 [95% CI 1.23-3.25] and OR 1.04 [95% CI 1.02-1.06] respectively) while female gender, and lower temperatures were negative predictors (OR 0.68 [95%0.47-0.98] and OR 0.47 [95% CI 0.32-0.67] respectively). Antibiotics were prescribed by a physician 89% of the time; the most common one being Amoxicillin/Clavulanic Acid (39%). The antibiotic group got more blood tests (57% vs 45%) and Chest X-Rays (37% vs 25%). Overall, the percent of SBIs (and pneumonias) was statistically the same in both groups (6.5% in the No-antibiotic group VS 3.6%). CONCLUSIONS: Children presenting on antibiotics and off antibiotics were significantly different in their presentation and management, although the overall percentages of SBI were similar in each group. Further investigations into this subgroup of febrile children are needed.

Characteristics of lupus and lupus nephritis at a tertiary care center in Lebanon.

INTRODUCTION: Systemic lupus erythematosus affects 4.8-78.5 people per 100,000 worldwide, 90% of whom are females. Geography and ethnicity have been shown to significantly affect the prevalence and natural history of the disease. Lupus nephritis affects around half of patients with systemic lupus erythematosus. Data about systemic lupus erythematosus and lupus nephritis in the Middle East are still scarce. In this study, we aimed to describe the characteristics of systemic lupus erythematosus and lupus nephritis at a tertiary care center in Lebanon. METHODS: This is a retrospective chart review of all biopsy-proven lupus nephritis patients admitted to the American University of Beirut medical center between January 2000 and December 2018. Patients above 12 years of age who had any International Society of Nephrology/Renal Pathology Society (ISN/RPS) class of lupus nephritis on their renal biopsy were included in the study. RESULTS: The study included 55 patients with lupus nephritis. Upon presentation of systemic lupus erythematosus, the most common clinical feature was arthritis, seen in 83% of patients, followed by anemia (82%) and malar rash (48%). In total 93% had positive ANA, 89% had positive anti-dsDNA and 98% of patients had proteinuria. The most common ISN/RPS class of lupus nephritis in our series was IV (49%). At the time of the biopsy 15% of patients underwent dialysis. At 6 months, 11/27 had complete remission, 6/27 had partial remission and 10/27 had no remission. At 1 year, 8/23 had complete remission, 4/23 had partial remission and 11/23 had no remission. During the study period, 15 out of 35 patients available for analysis had chronic kidney disease (CKD) and six out of 34 patients developed end-stage kidney disease requiring renal replacement therapy. In comparison to other series in the region, our series had more males affected, higher creatinine at the time of biopsy and greater degree of proteinuria. CONCLUSION: Our study provided insight on the demographics, characteristics, and outcomes of lupus nephritis in Lebanon. Interestingly, male gender was present in a quarter of patients. This warrants further investigation and confirmation. We are hoping to expand this experience into a national prospective registry to further characterize this entity in our region.

Can CT and MRI features differentiate benign from malignant meningiomas?

AIM: To highlight magnetic resonance imaging (MRI) and computed tomography (CT) characteristics in distinguishing benign from high-grade meningiomas (World Health Organization [WHO] grade II and III) preoperatively. MATERIALS AND METHODS: Seventy-one patient who underwent surgical resection of intracranial meningiomas at American University of Beirut Medical Center between 2008 and 2017 were evaluated for various CT and MRI features. The correlation between imaging findings, histopathological grading, and operative reports was analysed via univariate and multivariate logistic regression analysis. MRI specificity and sensitivity in detecting meningioma brain invasion as compared to operative reports post-resection was detected. RESULTS: Univariate analysis results showed a significant correlation between high-grade meningiomas and several MRI features including tumour size and volume (p=0.002,0.02), heterogeneous enhancement (p<0.0001), presence of intra-tumoural necrosis (p<0.0001), ill-defined margin (p=0.003), bone erosion (p=0.004), brain invasion (p=0.001), and a higher rate of recurrence (p=0.007) Only brain invasion and presence of intra-tumoural necrosis were significantly correlated with the high-grade meningioma in multivariate analysis. Hyperostosis of the adjacent skull was the only significant CT feature predicting the presence of low-grade meningioma. MRI showed 79% specificity and 20% sensitivity, 92% negative predictive value and 7% positive predictive value in detecting meningioma brain invasion. CONCLUSION: MRI has a promising role in predicting meningioma grade prior to resection, which can directly impact patients' management protocols regarding surgical planning and complications.

Mullins effect in polyethylene and its dependency on crystal content: A network alteration model.

This contribution is focused on the Mullins effect in polyethylene. An ultra-low-density polyethylene with 0.15 crystal content, a low-density polyethylene with 0.3 crystal content and a high-density polyethylene with 0.72 crystal content are subjected to cyclic stretching over a large strain range. Experimental observations are first reported to examine how the crystal content influences the Mullins effect in polyethylene. It is found that the cyclic stretching is characterized by a stress-softening, a hysteresis and a residual strain, whose amounts depends on the crystal content and the applied strain. A unified viscohyperelastic-viscoelastic-viscoplastic constitutive model is proposed to capture the polyethylene response over a large strain range and its crystal-dependency. The macro-scale polyethylene response is decomposed into two physically distinct sources, a viscoelastic-viscoplastic intermolecular part and a viscohyperelastic network part. The local inelastic deformations of the rubbery amorphous and crystalline phases are considered by means of a micromechanical treatment using the volume fraction concept. Experimentally-based material kinetics are designed by considering the Mullins effect crystal-dependency and are introduced into the constitutive equations to capture the experimental observations. It is shown that the model is able to accurately reproduce the Mullins effect in polyethylene over a large strain range. The inherent deformation mechanisms are finally presented guided by the proposed constitutive model.

Oestrogen receptors beta genotype in infertile Egyptian men with nonobstructive azoospermia.

In a prospective study, the polymorphism of oestrogen receptor ß gene was investigated in nonobstructive azoospermia patients. Ninety infertile patients with nonobstructive azoospermia diagnosed after two semen analysis, 2 weeks apart and negative testicular sperm extraction during intracytoplasmic sperm injection, and 60 fertile men as controls were enrolled in the study. Semen analysis, hormonal profile and allele-specific PCR reaction were performed to detect variants of the RsaI polymorphism of the oestrogen receptor ß gene for all patients and controls. The mean patient's age was significantly lower than the mean age of the controls (P < 0.05). There was a significant increase in the mean serum levels of FSH, LH, free testosterone and E2 and significant decrease in total testosterone in patients than controls (P < 0.05). In the patients, the frequency of the homozygous GG, heterozygous AG and homozygous AA genotype was 83.3%, 14.3% and 3.3% respectively, whereas their frequencies in the controls were 95%, 5% and 0% respectively (odds ratio 3.8). There is no significant correlation between ERß polymorphisms and patient's age or pituitary and sex hormones (P > 0.05). Our findings suggested that in Egyptian population, genetic mutation in ERß is associated with the risk of nonobstructive azoospermia.

Facile access to a heterocyclic, sp(3)-rich chemical scaffold via a tandem condensation/intramolecular nitrone-alkene [3+2] cycloaddition strategy.

A heterocyclic, sp(3)-rich chemical scaffold was synthesised in just 6 steps via a highly regio- and diastereo-selective tandem nitrone formation/intramolecular nitrone-alkene [3+2] cycloaddition reaction. A library of 543 lead-like compounds based on the scaffold core has been produced.

Abnormal interhemispheric connectivity in neonates with D-transposition of the great arteries undergoing cardiopulmonary bypass surgery.

BACKGROUND AND PURPOSE: Neonates with severe CHD require CPB within the first days of life. White matter injury can occur before surgery, and this may impair the long-term neurodevelopmental and psychosocial outcome. The purpose of this study was to assess the microstructural development of the CC in infants with CHD before and after CPB for transposition of the great arteries. MATERIALS AND METHODS: Fifteen patients with CHD and 11 age-matched HC were recruited. We separately quantified the parallel (E1) and perpendicular (E23) diffusions, the ADC, and FA of the genu of the CC and splenium of the CC before and after surgery. RESULTS: In presurgical measures of the genu of the CC, higher E23 (P = .018), higher ADC (P = .026), and lower FA (P = .033) values were measured compared with those in HC. In the postsurgery scans, the genu of the CC had higher E23 (P = .013), higher ADC (P = .012), and lower FA (P = .033) values compared with those in HC. There was no significant difference in any DTI indices between the pre- and postsurgical groups. CONCLUSIONS: We report abnormal microstructural development in the genu of the CC of infants with d-TGA before and after CPB. High E23, high ADC, and low FA values in the genu of the CC may be explained by abnormal axonal pruning, thinner myelin sheaths, smaller axonal diameters, or more oligodendrocytes. It appears that the genu of the CC is more vulnerable than the splenium of the CC in patients with CHD and may serve as a biomarker to identify infants at highest risk for adverse neurodevelopmental outcome.

Magnetic Resonance Imaging Estimation of Longitudinal Relaxation Rate Change (ΔR1) in Dual Gradient Echo Sequences Using an Adaptive Model.

Magnetic Resonance Imaging (MRI) estimation of contrast agent concentration in fast pulse sequences such as Dual Gradient Echo (DGE) imaging is challenging. An Adaptive Neural Network (ANN) was trained with a map of contrast agent concentration estimated by Look-Locker (LL) technique (modified version of inversion recovery imaging) as a gold standard. Using a set of features extracted from DGE MRI data, an ANN was trained to create a voxel based estimator of the time trace of CA concentration. The ANN was trained and tested with the DGE and LL information of six Fisher rats using a K-Fold Cross-Validation (KFCV) method with 60 folds and 10500 samples. The Area Under the Receiver Operator Characteristic Curve (AUROC) for 60 folds was used for training, testing and optimization of the ANN. After training and optimization, the optimal ANN (4:7:5:1) produced maps of CA concentration which were highly correlated (r =0.89, P < 0.0001) with the CA concentration estimated by the LL technique. The estimation made by the ANN had an excellent overall performance (AUROC = 0.870).

Diffusion tensor imaging study of the cortical origin and course of the corticospinal tract in healthy children.

BACKGROUND AND PURPOSE: Several studies have questioned the traditional belief that the corticospinal tract (CST) arises exclusively from the precentral gyrus and passes through the anterior half of the posterior limb of the internal capsule (PLIC) in humans; however, no direct evidence existed from structural imaging, and developmental aspects of CST origin have not been clarified. We used diffusion tensor imaging (DTI) tractography to test the hypotheses that CST can originate from both pre- and postcentral gyri and is located posteriorly in the PLIC, and we also determined how age, sex, or handedness affected these locations. MATERIALS AND METHODS: Forty-two healthy children (2.6-17.5 years of age; 20 girls) underwent DTI. Subsequently, tractography was performed on the basis of fiber assignment by continuous tracking (FACT) algorithm and brute force approach, with a fractional anisotropy (FA) threshold of <0.2 and an angle threshold of >50 degrees . The CST was isolated by using a knowledge-based region-of-interest approach, and its cortical origin and location on the PLIC was determined. RESULTS: DTI revealed that the CST originated from both pre- and postcentral gyri in 71.4% of hemispheres, from the precentral gyrus only in 19%, and from the postcentral gyrus only in 7.1%. The overall distribution was similar in both hemispheres. However, children with CST originating from both pre- and postcentral gyri were older (mean, 11.1 years of age) than those with precentral origin (mean, 5.8 years of age) or postcentral origin (mean, 7.8 years of age) only (P = .00003). The center of the CST was localized at 65% of the length (from its anterior margin) of the PLIC, and the CST occupied 26.5% of its anteroposterior length. There was a significant positive correlation between age and FA of the CST (r = 0.49; P = .002). The volume of the precentral portion of the left CST was significantly higher than that of its postcentral portion (P = .01) and that of the right CST (P = .0002). The pattern of cortical origin of CST, its location at the level of PLIC, and its volume and FA were unaffected by sex or handedness. CONCLUSIONS: The CST most frequently originates from both pre- and postcentral gyri, especially in older children, and is typically centered approximately two thirds of the distance from the anterior margin of the PLIC and occupies about a quarter of its anteroposterior length. In young children, the CST can often be seen originating exclusively from the precentral gyrus by DTI.

Characteristics of abnormal diffusivity in normal-appearing white matter investigated with diffusion tensor MR imaging in tuberous sclerosis complex.

BACKGROUND AND PURPOSE: Although patients with tuberous sclerosis complex (TSC) manifest various structural abnormalities, we hypothesized that white matter (WM) structures that appear normal on conventional MR imaging may be accompanied by microstructural changes, such as gliosis and myelinization defects. Our objective was to determine in vivo whether there was evidence for WM microstructural changes by using diffusion tensor imaging (DTI). MATERIALS AND METHODS: We used DTI to evaluate diffusivity and anisotropy in normal-appearing WM (NAWM) of 6 children with TSC and 12 age-matched control subjects. The anterior and posterior limbs of the internal capsule, the external capsule, and the genu and splenium of the corpus callosum were assessed. We hypothesized that previously reported DTI abnormalities of NAWM in patients with TSC may not be equal in all diffusion directions as measured by the major, middle, and minor eigenvalues. RESULTS: When combining NAWM regions in patients with TSC, we observed a significant increase in mean diffusivity (P = .003) and a decrease in anisotropy (P = .03) compared with those of controls. However, the increase in diffusivity was more pronounced in directions orthogonal to the axons measured by the minor and middle eigenvalues (P = .005) than by the major eigenvalue (P = .02). CONCLUSION: Our findings revealed a decrease in anisotropy and an increase in longitudinal and radial diffusivities in NAWM beyond the location of TSC lesions seen on conventional MR imaging. The axonal microstructural changes suggested by our study may be related to changes in myelin packing due to giant cells accompanied by gliosis and myelination defects known to occur in TSC WM.

Multimodality imaging of cortical and white matter abnormalities in Sturge-Weber syndrome.

BACKGROUND AND PURPOSE: Impaired cortical venous outflow and abnormal deep venous collaterals are common in Sturge-Weber syndrome (SWS), but their relation to brain metabolism and function is poorly understood. In this study, advanced MR imaging techniques, such as susceptibility-weighted imaging (SWI) and diffusion tensor imaging (DTI), were applied in conjunction with positron-emission tomography (PET), to assess cortical and white matter structural abnormalities and their relation to cortical glucose metabolism and cognitive functions in children with unilateral SWS. MATERIALS AND METHODS: Thirteen children (age, 1.5-10.3 years) with unilateral SWS underwent MR imaging with SWI and DTI, glucose metabolism PET, and comprehensive neuropsychologic assessment prospectively. The MR imaging and PET images were coregistered and cortical regions showing decreased glucose metabolism were compared with locations of SWI signal intensity abnormalities, changes in white matter water diffusion, and cognitive functions. RESULTS: SWI detected both cortical abnormalities (n=8) and deep transmedullary veins (n=9), including those in young children with no cortical SWI signal intensity changes. These veins were often located under cortex adjacent to hypometabolic regions. DTI showed abnormal water diffusion both under hypometabolic cortex and in adjacent white matter with collateral veins. Cognitive dysfunction was associated with abnormal water diffusion in the posterior white matter. CONCLUSIONS: Transmedullary venous collaterals can be detected early by SWI and persist in white matter adjacent to damaged cortex in children with SWS. Microstructural white matter damage extends beyond cortical abnormalities and may contribute to cognitive impairment. SWI and DTI can be incorporated into clinical MR imaging acquisitions to objectively assess microstructural abnormalities at different stages of SWS.

WT1-mediated gene regulation in early urogenital ridge development.

The Wilms tumor protein WT1 is involved in the development of several organs, including the gonads. WT1 mutations in humans lead to syndromes associated with impaired sexual development and Wt1 knockout mice show regression of gonad anlagen. As a transcription factor, WT1 fulfills its function by regulating a set of target genes. With respect to gonad development only few in vivo WT1 targets, e.g. steroidogenic factor 1 (SF1) have been identified so far. To get a comprehensive view of WT1 targets in the gonad, we compared gene expression in urogenital ridges of wild-type and Wt1(-/-) embryos. We found almost 150 genes differentially expressed higher than factor three, using microarray analysis. To confirm these results we performed quantitative real-time RT-PCR for many genes and observed a high degree of concordance between microarray and real-time RT-PCR results. Employing in situ hybridization we found 'WT1 activated genes' to be expressed in gonads, mesonephroi and coelomic epithelium--those parts of the urogenital ridge with Wt1 expression. Interestingly, many of the differentially expressed genes are known to show sex-specific expression at later time-points. These results provide a basis for investigation of developmental pathways in the urogenital ridge downstream of WT1 and for identification of new candidate genes involved in early urogenital ridge development. For example we provide a first potential target of WT1 in the coelomic epithelium--Muc16, and a gene regulated by the WT1 target SF1--Gata4.

Assessment of dry heat exchanges in newborns: influence of body position and clothing in SIDS.

A dramatic decrease of sudden infant death syndrome (SIDS) has been noted following the issuance of recommendations to adopt the supine sleeping position for infants. It has been suggested that the increased risk could be related to heat stress associated with body position. In the present study, the dry heat losses of small-for-gestational-age newborns nude or clothed were assessed and compared to see whether there is a difference in the ability to lose heat between the prone and supine positions. An anthropomorphic thermal mannequin was exposed to six environmental temperatures, ranging between 25 and 37 degrees C, in a single-walled, air-heated incubator. The magnitudes of heat losses did not significantly differ between the two body positions for the nude (supine 103.46 +/- 29.67 vs. prone 85.78 +/- 34.91 W/m(2)) and clothed mannequin (supine 59.35 +/- 21.51 vs. prone 63.17 +/- 23.06 W/m(2)). With regard to dry heat exchanges recorded under steady-state conditions, the results show that there is no association between body position and body overheating.

Occupational mobility of heads of households migrating to Medina.

"The aim of this study is to determine the effect of internal and external migration on the occupational mobility of the heads of households migrating to Medina [Saudi Arabia]....[It] is based on a survey of families in Medina which was conducted by the author in 1986/1987." The results show that "the majority of the migrants were able to achieve positive vocational mobility as a result of their migration. However, there are some distinctions in the extent of this positiveness between Saudi Arabian and non-Saudi Arabian migrants, as well as between urban and rural migrants.... The main factors affecting migration to Medina are difference in income, as well as in the educational level at origin and at destination."

Chemical and nutritional assessment of sweetpotato proteins.

The solubility of sweetpotato nitrogen increased outside the pH range 3-6 for the pulp, and 2-5 for the peel of the two varieties namely, "Abees" and "Giza 69". The minimum nitrogen extractability occurred between the pH range 3-4, and 4-5 for the peel and pulp, respectively. The sweetpotato protein isolates were prepared separately from both peel and pulp of the two varieties. The former had the highest values of carbohydrates and ash while the latter had the highest values of protein and fat. The in-vitro digestibility of sweetpotato proteins and casein by pepsin-pancreatin was studied. Casein was more easily digested than the proteins of sweetpotatoes, whose digestibilities were higher in the pulp than in the peel of the two varieties. No trypsin inhibitor activity was detected in peel and pulp of both varieties under test. The effect of the variety of sweetpotatoes on the protein patterns was studied using the polyacrylamide gel electrophoresis and varietal specific patterns were obtained.

Regional and urban population size weights in Saudi Arabia, 1962-1974.

"The aim of this paper is to study the development of population weights for regions and urban centres in Saudi Arabia through the period 1962-1974. In order to achieve this aim some non-parametric statistical rules have been used such as rank-size rule and the four-city index. The results show non-balanced distribution of population on both regional and urban scales. The concentration of people in urban centres is more pronounced than the concentration in regions. This is due to internal and external movement of population towards large-sized urban centres."