2,197 research outputs found
Static fluid magnetic resonance urography in evaluation of ureteral ectopia: Experience in 10 pediatric cases
Introduction: Ectopic ureters are often very difficult to diagnose with conventional imaging modalities especially in children. Magnetic resonance urography (MRU) has been recently investigated as a problem-solving tool for the evaluation of various congenital urogenital anomalies with favorable results.Aim of the work: To assess the value of static fluid MRU in diagnosing ectopic ureters in childhood.Patientsand methods: Ten out of 14 pediatric patients with suspected ureteral ectopia (as suggested by clinical or conventional imaging techniques) were included in this study and prospectively studied by MRUaiming to confirmthe suspected diagnosis. The examinations were done on 1.5T machines using static fluid T2W-MRU sequences. Ultrasound examinations were done for all patients. Voiding cystourethrogram (VCUG) was done for 8 patients to exclude vesico-ureteric reflux or urethral anomalies.Results: All studied patients had dilated collecting systems. Static fluid MRU was able to detect the site of ectopic ureteric insertion in all 10 patients. It was superior to ultrasound in evaluation of 8 cases with complex duplex systems. In one patient with multiple congenital anomalies, MRU clearly demonstrated the urinary and extra-urinary anomalies. The final diagnosis was confirmed by surgical or endoscopic data in all patients.Conclusions: In dilated collecting systems, static fluid MRU can provide detailed assessment of the collecting systems and ureters as well as adequately detect ureteral ectopia. MRU should be recommended whenever a ureteric insertion anomaly is suspected.Keywords: Magnetic resonance urography; MRU; Ectopic ureter; Ureteral ectopia; Ureteric insertion anomalie
Mitochondrial alterations in children with chronic liver disease
Background: Over recent years it has become apparent that the hepatocyte mitochondrion functions both as a cause and as a target of liver injury. Resultant dysfunction of mitochondria yields deficient oxidative phosphorylation, increased generation of reactive oxygen species, impairment of other metabolic pathways and activation of both necrotic and apoptotic pathways of cellular death.Methods: This study was conducted on 26 children and adolescents with chronic liver disease who presented to or were following up in the Pediatric Hepatology Clinic, Children’s Hospital, Ain-Shams University. They were divided into three groups according to the aetiology of liver disease (GI=patients with Wilson’s disease (WD), GII=patients with chronic hepatitis C, GIII=patients with chronic liver disease other thanWilson’s and chronic hepatitis C).Ultrasound-guided gun liver biopsies were performed, under local anaesthesia for all the 26 patients, using a modified 18-gauge truecut needle. Two liver biopsy cores were taken from each patient. One for light and electron microscopic examinations and the other was immediately immersed in liquid nitrogen to be frozen and used forstudying mitochondrial DNA deletions by PCR.Results: Liver steatosis was higher in the group of patients with Wilson’s disease and other liver disease. Electron microscopic examination of the mitochondria revealed significant mitochondrial pleomorphism in patients with Wilson’s disease and patients with chronic hepatitis C infection. Enlarged mitochondria were found to bemore prevalent among patients with chronic hepatitis infection.Three of our patients (11.53%) had mitochondrial DNA deletions. We developed scoring system for mitochondrial affection in our patients, 7 patients (32%) were considered to have mild mitochondrial affection,9 patients (41%) had moderate mitochondrial affection, while 6 patients (27%) had severe mitochondrial affection. Four of the studied patients had no mitochondrial affection.Conclusion: Mitochondria affection is common in chronic liver disease. This mitochondrial affection might be responsible for some of the chronic liver disease manifestation such as easy fatiguability and steatosis
A Special Homotopy Continuation Method For A Class of Polynomial Systems
A special homotopy continuation method, as a combination of the polyhedral
homotopy and the linear product homotopy, is proposed for computing all the
isolated solutions to a special class of polynomial systems. The root number
bound of this method is between the total degree bound and the mixed volume
bound and can be easily computed. The new algorithm has been implemented as a
program called LPH using C++. Our experiments show its efficiency compared to
the polyhedral or other homotopies on such systems. As an application, the
algorithm can be used to find witness points on each connected component of a
real variety
Mitochondria directly influence fertilisation outcome in the pig
The mitochondrion is explicitly involved in cytoplasmic regulation and is the cell's major generator of ATP. Our aim was to determine whether mitochondria alone could influence fertilisation outcome. In vitro, oocyte competence can be assessed through the presence of glucose-6-phosphate dehydrogenase (G6PD) as indicated by the dye, brilliant cresyl blue (BCB). Using porcine in vitro fertilisation (IVF), we have assessed oocyte maturation, cytoplasmic volume, fertilisation outcome, mitochondrial number as determined by mtDNA copy number, and whether mitochondria are uniformly distributed between blastomeres of each embryo. After staining with BCB, we observed a significant difference in cytoplasmic volume between BCB positive (BCB+) and BCB negative (BCB-) oocytes. There was also a significant difference in mtDNA copy number between fertilised and unfertilised oocytes and unequal mitochondrial segregation between blastomeres during early cleavage stages. Furthermore, we have supplemented BCB- oocytes with mitochondria from maternal relatives and observed a significant difference in fertilisation outcomes following both IVF and intracytoplasmic sperm injection (ICSI) between supplemented, sham-injected and non-treated BCB- oocytes. We have therefore demonstrated a relationship between oocyte maturity, cytoplasmic volume, and fertilisation outcome and mitochondrial content. These data suggest that mitochondrial number is important for fertilisation outcome and embryonic development. Furthermore, a mitochondrial pre-fertilisation threshold may ensure that, as mitochondria are diluted out during post-fertilisation cleavage, there are sufficient copies of mtDNA per blastomere to allow transmission of mtDNA to each cell of the post-implantation embryo after the initiation of mtDNA replication during the early postimplantation stages
Construction of large-volume tissue mimics with 3D functional vascular networks
We used indirect stereolithography (SL) to form inner-layered fluidic networks in a porous scaffold by introducing a hydrogel barrier on the luminal surface, then seeded the networks separately with human umbilical vein endothelial cells and human lung fibroblasts to form a tissue mimic containing vascular networks. The artificial vascular networks provided channels for oxygen transport, thus reducing the hypoxic volume and preventing cell death. The endothelium of the vascular networks significantly retarded the occlusion of channels during whole-blood circulation. The tissue mimics have the potential to be used as an in vitro platform to examine the physiologic and pathologic phenomena through vascular architecture.ope
Steam reforming on transition-metal carbides from density-functional theory
A screening study of the steam reforming reaction (CH_4 + H_2O -> CO + 3H_2)
on early transition-metal carbides (TMC's) is performed by means of
density-functional theory calculations. The set of considered surfaces includes
the alpha-Mo_2C(100) surfaces, the low-index (111) and (100) surfaces of TiC,
VC, and delta-MoC, and the oxygenated alpha-Mo_2C(100) and TMC(111) surfaces.
It is found that carbides provide a wide spectrum of reactivities towards the
steam reforming reaction, from too reactive via suitable to too inert. The
reactivity is discussed in terms of the electronic structure of the clean
surfaces. Two surfaces, the delta-MoC(100) and the oxygen passivated
alpha-Mo_2C(100) surfaces, are identified as promising steam reforming
catalysts. These findings suggest that carbides provide a playground for
reactivity tuning, comparable to the one for pure metals.Comment: 6 pages, 4 figure
Risk factors for MERS coronavirus infection in dromedary camels in Burkina Faso, Ethiopia, and Morocco, 2015
Understanding Middle East respiratory syndrome coronavirus (MERS-CoV) transmission in dromedary camels is important, as they consitute a source of zoonotic infection to humans. To identify risk factors for MERS-CoV infection in camels bred in diverse conditions in Burkina Faso, Ethiopia and Morocco, blood samples and nasal swabs were sampled in February-March 2015. A relatively high MERS-CoV RNA rate was detected in Ethiopia (up to 15.7%; 95% confidence interval (CI): 8.2-28.0), followed by Burkina Faso (up to 12.2%; 95% CI: 7-20.4) and Morocco (up to 7.6%; 95% CI: 1.9-26.1). The RNA detection rate was higher in camels bred for milk or meat than in camels for transport (p = 0.01) as well as in younger camels (p = 0.06). High seropositivity rates (up to 100%; 95% CI: 100-100 and 99.4%; 95% CI: 95.4-99.9) were found in Morocco and Ethiopia, followed by Burkina Faso (up to 84.6%; 95% CI: 77.2-89.9). Seropositivity rates were higher in large/medium herds (≥51 camels) than small herds (p = 0.061), in camels raised for meat or milk than for transport (p = 0.01), and in nomadic or sedentary herds than in herds with a mix of these lifestyles (p < 0.005).published_or_final_versio
Retinal microvascular parameters are not associated with reduced renal function in a study of individuals with type 2 diabetes
Abstract The eye provides an opportunistic “window” to view the microcirculation. There is published evidence of an association between retinal microvascular calibre and renal function measured by estimated glomerular filtration rate (eGFR) in individuals with diabetes mellitus. Beyond vascular calibre, few studies have considered other microvascular geometrical features. Here we report novel null findings for measures of vascular spread (vessel fractal dimension), tortuosity, and branching patterns and their relationship with renal function in type 2 diabetes over a mean of 3 years. We performed a nested case-control comparison of multiple retinal vascular parameters between individuals with type 2 diabetes and stable (non-progressors) versus declining (progressors) eGFR across two time points within a subset of 1072 participants from the GoDARTS study cohort. Retinal microvascular were measured using VAMPIRE 3.1 software. In unadjusted analyses and following adjustment for age, gender, systolic blood pressure, HbA1C, and diabetic retinopathy, no associations between baseline retinal vascular parameters and risk of eGFR progression were observed. Cross-sectional analysis of follow-up data showed a significant association between retinal arteriolar diameter and eGFR, but this was not maintained following adjustment. These findings are consistent with a lack of predictive capacity for progressive loss of renal function in type 2 diabetes
Prevalence of diabetic retinopathy in Tehran province: a population-based study
<p>Abstract</p> <p>Background</p> <p>To determine the prevalence and characteristics of diabetic retinopathy (DR) among Iranian patients with diabetes.</p> <p>Methods</p> <p>Design: population-based cross-sectional study.</p> <p>Participants: patients with diabetes aged 25 to 64 years in Tehran province, Iran. This survey was conducted from April to October 2007. The study sample was derived from the first national survey of risk factors for non-communicable disease. Diabetes mellitus was defined as a fasting plasma glucose of ≥ 7.0 mmol/l (126 mg/dl) or more, use of diabetic medications, or a physician's diagnosis of diabetes. All patients known to have diabetes underwent an eye examination by bio-microscope and indirect ophthalmoscope to check for any signs of DR through dilated pupils by + 78 lens. Participants were also interviewed and examined to determine their demographic characteristics, medical conditions and the regularity of their eye visits.</p> <p>Results</p> <p>Among 7989 screened patients, 759 (9.5%) had diabetes. Of them, 639 patients (84.2%) underwent eye examination. Five patients (0.7%) with media opacity were excluded. Of 634 examined patients with diabetes, 240 had some degree of diabetic retinopathy, and the overall standardized prevalence of any retinopathy was 37.0% (95% CI: 33.2-40.8), including 27.3% (95% CI: 23.7-30.8) (n = 175) with non-proliferative and 9.6% (95% CI: 7.3-11.9) (n = 65) with proliferative diabetic retinopathy. Clinically significant macular edema and vision-threatening retinopathy were detected in 5.8% (95% CI: 4.0-7.7) (n = 38) and 14.0% (95% CI: 11.3-16.7) (n = 95) of patients, respectively. Only 143 patients (22.6%) with diabetes had a history of regular eye examination.</p> <p>Conclusion</p> <p>This study demonstrated a high prevalence and poor control of DR in Tehran province. This suggests the need for adequate prevention and treatment in patients with diabetes.</p
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