232 research outputs found
Complications of Decompressive Craniectomy
Introduction:
Persistent elevation of intracranial pressure (ICP), if untreated, may lead to brain ischemia or lack of brain oxygen and even brain death.1-6,10 When standard treatments for elevated ICP are exhausted without any signs of improvement, decompressive craniectomy can be an effective alternative solution.7,19 Decompressive craniectomies (DC) have been used as a method of controlling intracranial pressure in patients with cerebral edema secondary to cerebral ischemia, subarachnoid hemorrhage (SAH), and traumatic brain injury (TBI), among others. 8-10 Several studies over the years have demonstrated the efficacy of this procedure.7-9,11,35,36 However, consensus is still lacking in the utility of DC as an effective first tier treatment for intractable intracranial pressure due to the rudimentary neurological outcome assessments, and the many complications associated with this procedure.11,12,59 There are a limited number of studies that have looked at complications secondary to the procedure itself.13-18 The majority of these studies only investigated the impact of this procedure in patients with traumatic brain injury. The purpose of this study is to investigate the rates of various complications associated with the decompressive craniectomy procedure in patients that did not suffer from traumatic brain injury, and to determine whether the same associations between preoperative parameters and development of complications can be made
Growth of Ordered Iron Oxide Nanowires for Photo-electrochemical Water Oxidation
This work reports the synthesis of ordered and vertically aligned iron oxide nanowires for photo-electrochemical (PEC) water oxidation. The nanowires exhibited promising PEC activity for water oxidation with saturated photocurrents of ∼0.8 mA cm-2 at 1.23 V vs RHE. Various factors inevitably affect their photochemical activity such as crystallinity, morphology, compositional gradient, and surface states. They were studied with HRTEM, EELS, and Raman shift techniques. The nanowires had complex compositional and morphological structures at nano and atomic scales. The nanowires annealed at 350 °C had an outer shell dominated by Fe3+ cations, while the core had mixed oxidation states of iron cations (+2 and +3). In contrast, nanowires annealed at 450 °C are fully oxidized with Fe3+ cations only and were found to be more active. At the same time, we observed anisotropic compositional gradients of nickel cations inside the iron oxide, originating from the nickel support film. Our work shows that the methodology used can affect the composition of the surface and near surface of the grown nanowires. It therefore points out the importance of a detailed analysis, in order to obtain a realistic structure-activity relationship in photo-electrocatalysis
Fumarate is an epigenetic modifier that elicits epithelial-to-mesenchymal transition.
Mutations of the tricarboxylic acid cycle enzyme fumarate hydratase cause hereditary leiomyomatosis and renal cell cancer. Fumarate hydratase-deficient renal cancers are highly aggressive and metastasize even when small, leading to a very poor clinical outcome. Fumarate, a small molecule metabolite that accumulates in fumarate hydratase-deficient cells, plays a key role in cell transformation, making it a bona fide oncometabolite. Fumarate has been shown to inhibit α-ketoglutarate-dependent dioxygenases that are involved in DNA and histone demethylation. However, the link between fumarate accumulation, epigenetic changes, and tumorigenesis is unclear. Here we show that loss of fumarate hydratase and the subsequent accumulation of fumarate in mouse and human cells elicits an epithelial-to-mesenchymal-transition (EMT), a phenotypic switch associated with cancer initiation, invasion, and metastasis. We demonstrate that fumarate inhibits Tet-mediated demethylation of a regulatory region of the antimetastatic miRNA cluster mir-200ba429, leading to the expression of EMT-related transcription factors and enhanced migratory properties. These epigenetic and phenotypic changes are recapitulated by the incubation of fumarate hydratase-proficient cells with cell-permeable fumarate. Loss of fumarate hydratase is associated with suppression of miR-200 and the EMT signature in renal cancer and is associated with poor clinical outcome. These results imply that loss of fumarate hydratase and fumarate accumulation contribute to the aggressive features of fumarate hydratase-deficient tumours.This work was supported by the Medical Research Council (UK). S.F. was supported by a Herchel Smith Research Studentship and K.F. by an MRC Career Development Award. E.R.M is supported by the ERC Advanced Researcher award 323004–ONCOTREAT. P.H.M. is supported by Senior Investigator Awards from the Wellcome Trust and NIHR. The Cambridge Human Research Tissue Bank and A.W. are supported by the NIHR Cambridge Biomedical Research Centre.This is the author accepted manuscript. The final version is available from Nature Publishing at http://dx.doi.org/10.1038/nature19353
Localized Giant Inflammatory Polyposis of the Ileocecum Associated with Crohn's Disease: Report of a Case
Although inflammatory polyposis is one of the common complications in patients with inflammatory bowel disease, it is rare that each poly grows up to more than 1.5 cm. We describe a case of localized giant inflammatory polyposis of the ileocecum associated with Crohn's disease. A 40-year-old man who had been followed for 28 years because of Crohn's disease was hospitalized for right lower abdominal pain after meals. Barium enema and colonoscopy showed numerous worm-like polyps in the ascending colon which grew up to the hepatic flexure of the colon from the ileocecum, causing an obstruction of the ileocecal orifice. Since histology of a biopsy specimen taken from the giant polyps showed no dysplasia, he was diagnosed with ileus due to the localized giant inflammatory polyposis. A laparoscopically assisted ileocecal resection was performed. The resected specimen showed that the giant polyps grew up into the ileocecum. Histological examination revealed inflammatory polyposis without neoplasm. Generally, conservative treatment is indicated for localized giant inflammatory polyposis because this lesion is regarded as benign. However, occasionally serious complications arise, requiring surgical treatment
Imaging localized energy states in silicon-doped InGaN nanowires using 4D electron microscopy
Introducing dopants into InGaN NWs is known to significantly improve their device performances through a variety of mechanisms. However, to further optimize device operation under the influence of large specific surfaces, thorough knowledge of ultrafast dynamical processes at the surface and interface of these NWs is imperative. Here, we describe the development of four-dimensional scanning ultrafast electron microscopy (4D S-UEM) as an extremely surface-sensitive method to directly visualize in space and time the enormous impact of silicon doping on the surface-carrier dynamics of InGaN NWs. Two time regimes of surface dynamics are identified for the first time in a 4D S-UEM experiment: an early time behavior (within 200 ps) associated with the deferred evolution of secondary electrons due to the presence of localized trap states that decrease the electron escape rate and a longer time scale behavior (several ns) marked by accelerated charge carrier recombination. The results are further corroborated by conductivity studies carried out in the dark and under illumination
Embolic stroke complicating Staphylococcus aureus endocarditis circumstantially linked to rectal trauma from foreign body: a first case report
BACKGROUND: Diagnostic and therapeutic instrumentation of the lower gastrointestinal tract has been reported to result in bacteremia and endocarditis. No such case has been reported in persons with a history of rectal foreign body insertion despite its potential for greater trauma. CASE PRESENTATION: A 58-year-old male was admitted with confusion and inability to speak. His past history was notable for hospitalization to extract a retained plastic soda bottle from the rectosigmoid two years prior. On examination, he was febrile, tachycardic and hypotensive. There was an apical pansystolic murmur on cardiac examination. He had a mixed receptive and expressive aphasia, and a right hemiparesis. On rectal examination he had perianal erythema and diminished sphincter tone. Magnetic resonance imaging of the brain showed infarction of the occipital and frontal lobes. Transesophageal Echocardiography of the heart revealed vegetations on the mitral valve. All of his blood culture bottles grew methicillin sensitive Staphylococcus aureus. He was successfully treated for bacterial endocarditis with intravenous nafcillin and gentamicin. The rectum is frequently colonized by Staphylococcus aureus and trauma to its mucosa can lead to bacteremia and endocarditis with this organism. In the absence of corroborative evidence such as presented here, it is difficult to make a correlation between staphylococcal endocarditis and anorectal foreign body insertion due to patients being less than forthcoming CONCLUSION: There is a potential risk of staphylococcal bacteremia and endocarditis with rectal foreign body insertion. Further studies are needed to explore this finding. Detailed sexual history and patient counseling should be made a part of routine primary care
Malignant neuroectodermal tumor with melanocytic and rhabdomyoblastic differentiation
Malignant melanoma can metastasize widely and vary significantly in its histological appearance; it rarely presents as a deep-seated mass without an obvious primary site elsewhere. Malignant peripheral nerve sheath tumor (MPNST) is a high-grade sarcoma characterized by conventional and epithelioid subtypes. MPNST can demonstrate heterologous differentiation, usually in the form of osteosarcomatous, chondrosarcomatous, or rhabdomyosarcomatous differentiation. MPNST does not harbor true melanocytic differentiation, although epithelioid MPNST typically is diffusely S-100 protein positive and superficially can resemble malignant melanoma. An unusual intra-abdominal mass was recently encountered with features of both melanoma and conventional or epithelioid MPNST containing a fascicular spindle cell component, an epithelioid component with melanocytic differentiation, as well as a rhabdomyosarcomatous component. The terminology “malignant neuroectodermal tumor with melanocytic and rhabdomyoblastic differentiation” is proposed to describe this neoplasm, reflecting the unusual concomittant lines of differentiation as well as offering a possible rationale for nosologically challenging aspects of this neoplasm
The influence of diabetes mellitus on the spectrum of uropathogens and the antimicrobial resistance in elderly adult patients with urinary tract infection
BACKGROUND: The role of Diabetes mellitus (DM) in the etiology and in the antimicrobial resistance of uropathogens in patients with urinary tract infection has not been well clarified. For this reason we have evaluated the spectrum of uropathogens and the profile of antibiotic resistance in both diabetic and non diabetic patients with asymptomatic urinary tract infection (UTI). METHODS: Urinary isolates and their patterns of susceptibility to the antimicrobials were evaluated in 346 diabetics (229 females and 117 males) and 975 non diabetics (679 females and 296 males) who were screened for significant bacteriuria (≥10(5 )CFU/mL urine). The mean age of diabetic and non diabetic patients was respectively 73.7 yrs ± 15 S.D. and 72.7 ± 24 (p = NS). RESULTS: Most of our patients had asymptomatic UTI. The most frequent causative organisms of bacteriuria in females with and without DM were respectively : E. coli 54.1% vs 58.2% (p = NS), Enterococcus spp 8.3% vs 6.5% (p = NS), Pseudomonas spp 3.9 vs 4.7% (p = NS). The most frequent organisms in diabetic and non diabetic males were respectively E. coli 32.5% vs 31.4% (p = NS), Enterococcus spp 9.4% vs 14.5% (p = NS), Pseudomonas spp 8.5% vs 17.2% (p = <0.02). A similar isolation rate of E. coli, Enterococcus spp and Pseudomonas spp was also observed in patients with indwelling bladder catheter with and without DM. No significant differences in resistance rates to ampicillin, nitrofurantoin, cotrimoxazole and ciprofloxacin of E. coli and Enteroccus spp were observed between diabetic and non diabetic patients. CONCLUSION: In our series of patients with asymptomatic UTI (mostly hospital acquired), diabetes mellitus per se does not seem to influence the isolation rate of different uropathogens and their susceptibility patterns to antimicrobials
Gallium Phosphide photoanode coated with TiO₂ and CoOₓ for stable photoelectrochemical water oxidation
Gallium Phosphide (GaP) has a band gap of 2.26 eV and a valance band edge that is more negative than the water oxidation level. Hence, it may be a promising material for photoelectrochemical water splitting. However, one thing GaP has in common with other III-V semiconductors is that it corrodes in photoelectrochemical reactions. Cobalt oxide (CoOₓ) is a chemically stable and highly active oxygen evolution reaction co-catalyst. In this study, we protected a GaP photoanode by using a 20 nm TiO₂ as a protection layer and a 2 nm cobalt oxide co-catalyst layer, which were both deposited atomic layer deposition (ALD). A GaP photoanode that was modified by CoOₓ exhibited much higher photocurrent, potential, and photon-to-current efficiency than a bare GaP photoanode under AM1.5G illumination. A photoanode that was coated with both TiO₂ and CoOₓ layers was stable for over 24 h during constant reaction in 1 M NaOH (pH 13.7) solution under one sun illumination
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