The sensitivity and specificity of the conventional symptoms and signs in making a diagnosis of acute appendicitis

Introduction: Simple appendicitis can progress to perforation, which is associated with a much higher morbidity and mortality. So, surgeons have therefore been inclined to operate when the diagnosis is probable rather than wait until it is certain. Objective: This study is designed to evaluate the sensitivity and specificity of clinical examination in the diagnosis of acute appendicitis.Methods: The study included 866 patients of acute appendicitis who had undergone appendicectomy with preoperative diagnosis of acute appendicitis. They were analyzed retrospectively. The parameters evaluated were age/gender, clinical presentation (signs and symptoms) and total white blood cell counts. The operative findings were recorded and the inflammation of the appendix was graded into normal, acutely inflamed and gangrenous.Results: Clinical diagnosis was made correctly in 807 (93.2%) of the patients. White blood cells count ranged from 3.70 to 45.30 /mm3 (mean 17.5353 /mm3). It wa

A New Economic Dispatch for Coupled Transmission and Active Distribution Networks Via Hierarchical Communication Structure

Traditionally, the economic dispatch problem (EDP) of the bulk generators connected to transmission networks (TNs) is solved in a centralized dispatching center (CDC) while modeling distribution networks as passive loads. With the increasing penetration levels of distributed generation, coordinating the economic dispatch between TNs and active distribution networks (ADNs) became vital to maximizing system efficiency. This article proposes a hierarchical communication structure, which requires minimal upgrades to the CDC, for solving the EDP of coupled TNs and ADNs. Based on the minimal data transfer between the CDC and distribution network operators, the problem is formulated and solved while considering the network losses in both TNs and ADNs. Furthermore, a sensitivity analysis is conducted to assess the effect of the ratio of the distribution lines on the economic dispatch solution and the operational cost of the system. The numerical results demonstrate the effectiveness of the proposed centralized scheme and highlight the significance of considering the network losses of both TNs and ADNs when solving the EDP. The results show that the proposed framework can achieve savings of up to 17.98% by taking into account the network losses of TNs and ADNs

Genetic heterogeneity in spondylo-epimetaphyseal dysplasias: a clinical and radiological study

Introduction: Spondylo-epi-metaphyseal dysplasias (SEMD) are a heterogeneous group of skeletal disorders characterized by defective growth and modeling of the spine and long bones. Different types are described in the literature. Accurate classification of SEMDs is essential for proper genetic counseling. Patients and Methods: This study included 20 cases of SEMDs diagnosed by clinical and radiological findings. Cases were classified based on additional associated clinical and/or radiological features into 7 subtypes. Different subtypes were discussed with review of the literature. Results: The study illustrated the heterogeneity of SEMDs and emphasized the importance of detailed and meticulous clinical genetic and biochemical evaluation in addition to comprehensive radiological investigations for such group of disorders. It also recommends further molecular studies to identify the molecular bases of the different types. Keywords: Spondyloepimetaphyseal dysplasias, Genetic heterogeneity, Dyggve- Melchior-Clausen dysplasia, Glycoaminoglycans. Egypt. J. Hum. Genet Vol. 8 (2) 2007: pp. 147-17

Liver transplantation: Intraoperative changes in coagulation factors in 100 first transplants

Six intraoperative blood samples were obtained at intervals from each of 100 individuals undergoing their first liver transplants. The patients fell into the following diagnostic categories: postnecrotic cirrhosis 28, primary biliary cirrhosis 20, sclerosing cholangitis 19, miscellaneous diseases 14, carcinoma/neoplasia 12 and fulminant hepatitis 7. Coagulation factor values in the initial (baseline) blood samples varied by patient diagnosis. In general, all factor levels were reduced except factor VIII:C, which was increased to almost twice normal. The slight intraoperative changes in factors II, VII, IX, X, XI and XII suggested that a steady‐state relationship existed between depletion (consumption/bleeding) and repletion (transfusion, transit from extra‐ to intravascular space), even in the anhepatic state. In contrast, there were rapid and very significant falls in factor VIII and fibrinogen and a less pronounced decrease in factor V, all reaching their nadirs in early to mid‐Stage III. The cause of these coagulation changes appears to be activation of the fibrinolytic system. Copyright © 1989 American Association for the Study of Liver Disease

Lifshitz spacetimes from AdS null and cosmological solutions

We describe solutions of 10-dimensional supergravity comprising null deformations of $AdS_5\times S^5$ with a scalar field, which have $z=2$ Lifshitz symmetries. The bulk Lifshitz geometry in 3+1-dimensions arises by dimensional reduction of these solutions. The dual field theory in this case is a deformation of the N=4 super Yang-Mills theory. We discuss the holographic 2-point function of operators dual to bulk scalars. We further describe time-dependent (cosmological) solutions which have anisotropic Lifshitz scaling symmetries. We also discuss deformations of $AdS\times X$ in 11-dimensional supergravity, which are somewhat similar to the solutions above. In some cases here, we expect the field theory duals to be deformations of the Chern-Simons theories on M2-branes stacked at singularities.Comment: Latex, 29pgs, v3. references, minor clarifications (subsection on Lifshitz geometry seen by scalar probes) added, to appear in JHE

Probe Branes, Time-dependent Couplings and Thermalization in AdS/CFT

We present holographic descriptions of thermalization in conformal field theories using probe D-branes in AdS X S space-times. We find that the induced metrics on Dp-brane worldvolumes which are rotating in an internal sphere direction have horizons with characteristic Hawking temperatures even if there is no black hole in the bulk AdS. The AdS/CFT correspondence applied to such systems indeed reveals thermal properties such as Brownian motions and AC conductivities in the dual conformal field theories. We also use this framework to holographically analyze time-dependent systems undergoing a quantum quench, where parameters in quantum field theories, such as a mass or a coupling constant, are suddenly changed. We confirm that this leads to thermal behavior by demonstrating the formation of apparent horizons in the induced metric after a certain time.Comment: LaTeX, 47 pages, 14 figures; Typos corrected and references added (v2); minor corrections, references added(v3

Global burden of human brucellosis : a systematic review of disease frequency

BACKGROUND: This report presents a systematic review of scientific literature published between 1990-2010 relating to the frequency of human brucellosis, commissioned by WHO. The objectives were to identify high quality disease incidence data to complement existing knowledge of the global disease burden and, ultimately, to contribute towards the calculation of a Disability-Adjusted Life Years (DALY) estimate for brucellosis.METHODS/PRINCIPAL FINDINGS: Thirty three databases were searched, identifying 2,385 articles relating to human brucellosis. Based on strict screening criteria, 60 studies were selected for quality assessment, of which only 29 were of sufficient quality for data analysis. Data were only available from 15 countries in the regions of Northern Africa and Middle East, Western Europe, Central and South America, Sub-Saharan Africa, and Central Asia. Half of the studies presented incidence data, six of which were longitudinal prospective studies, and half presented seroprevalence data which were converted to incidence rates. Brucellosis incidence varied widely between, and within, countries. Although study biases cannot be ruled out, demographic, occupational, and socioeconomic factors likely play a role. Aggregated data at national or regional levels do not capture these complexities of disease dynamics and, consequently, at-risk populations or areas may be overlooked. In many brucellosis-endemic countries, health systems are weak and passively-acquired official data underestimate the true disease burden.CONCLUSIONS: High quality research is essential for an accurate assessment of disease burden, particularly in Eastern Europe, the Asia-Pacific, Central and South America and Africa where data are lacking. Providing formal epidemiological and statistical training to researchers is essential for improving study quality. An integrated approach to disease surveillance involving both human health and veterinary services would allow a better understand of disease dynamics at the animal-human interface, as well as a more cost-effective utilisation of resources

Epidemiological impact of public health interventions against diabetes in Qatar: mathematical modeling analyses.

AIMS: To predict the epidemiological impact of specific, and primarily structural public health interventions that address lifestyle, dietary, and commuting behaviors of Qataris as well as subsidies and legislation to reduce type 2 diabetes mellitus (T2DM) burden among Qataris. METHODS: A deterministic population-based mathematical model was used to investigate the impact of public health interventions on the epidemiology of T2DM among Qataris aged 20-79 years, which is the age range typically used by the International Diabetes Federation for adults. The study evaluated the impact of interventions up to 2050, a three-decade time horizon, to allow for the long-term effects of different types of interventions to materialize. The impact of each intervention was evaluated by comparing the predicted T2DM incidence and prevalence with the intervention to a counterfactual scenario without intervention. The model was parameterized using representative data and stratified by sex, age, T2DM risk factors, T2DM status, and intervention status. RESULTS: All intervention scenarios had an appreciable impact on reducing T2DM incidence and prevalence. A lifestyle management intervention approach, specifically applied to those who are categorized as obese and ≥35 years old, averted 9.5% of new T2DM cases by 2050. An active commuting intervention approach, specifically increasing cycling and walking, averted 8.5% of new T2DM cases by 2050. Enhancing consumption of healthy diets including fruits and vegetables, specifically a workplace intervention involving dietary modifications and an educational intervention, averted 23.2% of new T2DM cases by 2050. A subsidy and legislative intervention approach, implementing subsidies on fruits and vegetables and taxation on sugar-sweetened beverages, averted 7.4% of new T2DM cases by 2050. A least to most optimistic combination of interventions averted 22.8-46.9% of new T2DM cases by 2050, respectively. CONCLUSIONS: Implementing a combination of individual-level and structural public health interventions is critical to prevent T2DM onset and to slow the growing T2DM epidemic in Qatar

Holography for Einstein-Maxwell-dilaton theories from generalized dimensional reduction

We show that a class of Einstein-Maxwell-Dilaton (EMD) theories are related to higher dimensional AdS-Maxwell gravity via a dimensional reduction over compact Einstein spaces combined with continuation in the dimension of the compact space to non-integral values (`generalized dimensional reduction'). This relates (fairly complicated) black hole solutions of EMD theories to simple black hole/brane solutions of AdS-Maxwell gravity and explains their properties. The generalized dimensional reduction is used to infer the holographic dictionary and the hydrodynamic behavior for this class of theories from those of AdS. As a specific example, we analyze the case of a black brane carrying a wave whose universal sector is described by gravity coupled to a Maxwell field and two neutral scalars. At thermal equilibrium and finite chemical potential the two operators dual to the bulk scalar fields acquire expectation values characterizing the breaking of conformal and generalized conformal invariance. We compute holographically the first order transport coefficients (conductivity, shear and bulk viscosity) for this system.Comment: v2, Important additions: (1) discussion of the entropy current, (2) postulated zeta/eta bound is generically violated. Some comments and references added, typos corrected. 50 page

Tendinopathy—from basic science to treatment

Chronic tendon pathology (tendinopathy), although common, is difficult to treat. Tendons possess a highly organized fibrillar matrix, consisting of type I collagen and various 'minor' collagens, proteoglycans and glycoproteins. The tendon matrix is maintained by the resident tenocytes, and there is evidence of a continuous process of matrix remodeling, although the rate of turnover varies at different sites. A change in remodeling activity is associated with the onset of tendinopathy. Major molecular changes include increased expression of type III collagen, fibronectin, tenascin C, aggrecan and biglycan. These changes are consistent with repair, but they might also be an adaptive response to changes in mechanical loading. Repeated minor strain is thought to be the major precipitating factor in tendinopathy, although further work is required to determine whether it is mechanical overstimulation or understimulation that leads to the change in tenocyte activity. Metalloproteinase enzymes have an important role in the tendon matrix, being responsible for the degradation of collagen and proteoglycan in both healthy patients and those with disease. Metalloproteinases that show increased expression in painful tendinopathy include ADAM (a disintegrin and metalloproteinase)-12 and MMP (matrix metalloproteinase)-23. The role of these enzymes in tendon pathology is unknown, and further work is required to identify novel and specific molecular targets for therapy