34,099 research outputs found
Transthoracic three-dimensional echocardiography for the assessment of straddling tricuspid or mitral valves
Background The advent of 3D echocardiography has provided a technique which, potentially, could afford significant additional information over conventional cross-sectional echocardiography in the assessment of patients with straddling atrioventricular valves prior to surgical correction. Methods Eight patients, aged from 1 month to 9˙2 years, were examined with 3D echocardiography. All but three had discordant ventriculoarterial connections or double outlet right ventricle. Data suitable for reconstruction was acquired with transthoracic scanning. Right and left ventricular volumes were calculated in the 3D dataset. Results 3D echocardiography proved capable of defining the exact degree of straddling by imaging theproportion of tension apparatus attached to either side of the ventricular septum. It was able also to display the atrioventricular junction “en face”, thus permitting identification of the precise site of insertion of the muscular ventricular septum relative to the atrioventricular junction. This made it possiblefirst, to calculate the degree of valvar override, and second, to predict the location of the penetrating atrioventricular bundle. End-diastolic volume of the right ventricle in those with straddling tricuspid valves was 73 (61–83)% of normal, and, of the left ventricle in those with mitral valvar straddling 71 (40‐97)% of normal. Conclusions 3D echocardiography can aid in planning the optimal surgical procedure in patients with straddling or overrriding atrioventricular valves, as it provides diagnostic information superiorto standard crosssectional techniques. It also allows for exact measurement of the volumes of the respective ventricles
Depth mapping of integral images through viewpoint image extraction with a hybrid disparity analysis algorithm
Integral imaging is a technique capable of displaying 3–D images with continuous parallax in full natural color. It is one of the most promising methods for producing smooth 3–D images. Extracting depth information from integral image has various applications ranging from remote inspection, robotic vision, medical imaging, virtual reality, to content-based image coding and manipulation for integral imaging based 3–D TV. This paper presents a method of generating a depth map from unidirectional integral images through viewpoint image extraction and using a hybrid disparity analysis algorithm combining multi-baseline, neighbourhood constraint and relaxation strategies. It is shown that a depth map having few areas of uncertainty can be obtained from both computer and photographically generated integral images using this approach. The acceptable depth maps can be achieved from photographic captured integral images containing complicated object scene
Membranoproliferative glomerulonephritis in patients with chronic venous catheters: a case report and literature review.
Chronic indwelling catheters have been reported to be associated with membranoproliferative glomerulonephritis (MPGN) via the activation of the classical complement pathway in association with bacterial infections such as coagulase negative staphylococcus. We herein provide supporting evidence for the direct causal relationship between chronic catheter infections and MPGN via a case of recurrent MPGN associated with recurrent catheter infections used for total parenteral nutrition (TPN) in a man with short gut syndrome. We also present a literature review of similar cases and identify common clinical manifestations that may serve to aid clinicians in the early identification of MPGN associated with infected central venous catheterization or vice versa. The importance of routine monitoring of kidney function and urinalysis among patients with chronic central venous catheterization is highlighted as kidney injury may herald or coincide with overtly infected chronic indwelling central venous catheters
A detailed analysis of online pharmacy characteristics to inform safe usage by patients
Background: Evidence suggests that consumers potentially put themselves at risk when purchasing medicines on-line. Whilst logos provided by regulators may provide some level of reassurance there may be other indicators which could be used by consumers to identify those websites which may be safely used. Objectives: Identify characteristics of on-line pharmacies which are related to whether websites are regulated or non-regulated and those characteristics which could be used by patients to increase the likelihood of accessing regulated sites. Setting: Online pharmacies which supply diazepam, fluoxetine and simvastatin. Methods: Using piloted search terms via Google and Yahoo search engines, identified websites were screened for regulatory status, adherence to regulatory standards, administrative requirements, clinical assessment requirements and additional details deemed to be of relevance to a user. Characteristics of regulated and non-regulated (defined as those with an absence of a correctly linked regulatory logo) websites were compared to identify differences which could be used to improve patient safety. Main outcome measure: Regulatory status, adherence to regulatory standards, quality of information provision, barriers to medicines access. Results: 113 websites sold diazepam, fluoxetine and simvastatin; were identified within the first 100 results. Less than quarter were found to be regulated online pharmacies. 80 websites were willing to sell the medication without a prescription. The unregulated internet pharmacy websites (defined as those with an absence of a correctly linked regulatory logo) were found to adhere more closely to the clinical criteria, were less significantly likely to disclose a contact name and address, telephone number of the pharmacy or demand a prescription prior to sale (P\0.05, Fisher’s Exact). Conclusions: The three prescription-only medicines which are liable to abuse, have potentially serious interactions and require counselling to ensure patient safety are readily available via the internet. When purchasing medicines via this route UK consumers should be made aware of the importance of regulatory logos and additionally should ensure that the seller can be meaningfully contacted by the contact details provided. The provision of clinical information should not be used alone as an indication of the seller’s provenance
Direct conversion of methanol to n-C4H10 and H-2 in a dielectric barrier discharge reactor
Methanol is an important H-carrier and C1 chemical feedstock. In this paper, a direct conversion of methanol to n-C4H10 and H2 was achieved for the first time in a dielectric barrier discharge (DBD) non-thermal plasma reactor. The selective formation of n-C4H10 by limiting COx (x = 1 and 2) generation was obtained by optimizing different plasma processing parameters including the methanol inlet concentration, discharge power, and pre-heating temperature. The results showed that a higher methanol inlet concentration and a higher pre-heating temperature favors the formation of n-C4H10, while a higher methanol inlet concentration and a lower discharge power can effectively limit the formation of CO. The optimal selectivity for n-C4H10 (37.5%), H2 (28.9%) and CO (14%) was achieved, with a methanol conversion of 40.0%, at a methanol inlet concentration of 18 mol%, a discharge power of 30 W and a pre-heating temperature of 140 °C using N2 as a carrier gas. Value-added liquid chemicals (e.g., alcohols, acids, and heavy hydrocarbons) were also obtained from this reaction. Emission spectroscopy diagnostics reveals the formation of various reactive species (e.g., CH, C2, CN, H and metastable N2) in the CH3OH/N2 DBD. Possible reaction pathways for the formation of n-C4H10 were proposed and discussed
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Epidermal growth factor receptor variant III mediates head and neck cancer cell invasion via STAT3 activation.
Epidermal growth factor receptor (EGFR) is frequently overexpressed in head and neck squamous cell carcinoma (HNSCC) where aberrant signaling downstream of this receptor contributes to tumor growth. EGFR variant III (EGFRvIII) is the most commonly altered form of EGFR and contains a truncated ligand-binding domain. We previously reported that EGFRvIII is expressed in up to 40% of HNSCC tumors where it is associated with increased proliferation, tumor growth and chemoresistance to antitumor drugs including the EGFR-targeting monoclonal antibody cetuximab. Cetuximab was FDA-approved in 2006 for HNSCC but has not been shown to prevent invasion or metastasis. This study was undertaken to evaluate the mechanisms of EGFRvIII-mediated cell motility and invasion in HNSCC. We found that EGFRvIII induced HNSCC cell migration and invasion in conjunction with increased signal transducer and activator of transcription 3 (STAT3) activation, which was not abrogated by cetuximab treatment. Further investigation showed that EGF-induced expression of the STAT3 target gene HIF1-α, was abolished by cetuximab in HNSCC cells expressing wild-type EGFR under hypoxic conditions, but not in EGFRvIII-expressing HNSCC cells. These results suggest that EGFRvIII mediates HNSCC cell migration and invasion by increased STAT3 activation and induction of HIF1-α, which contribute to cetuximab resistance in EGFRvIII-expressing HNSCC tumors
Phytochemical Investigation and Anti-Microbial Activity of Clausena Anisata (Willd), Hook.
Background: Clausena anisata belongs to the family Rutaceae, a shrub widely used in West Africa for the treatment of bacterial and fungal infections of the skin including boils, ringworm and eczema. The study was designed to evaluate the antimicrobial activity and phytochemical screening of ethanol leaf extract of C. anisata (CLE).Method: Antimicrobial activity of CLE was investigated using agar well diffusion and micro-dilution methods against four Gram-positive bacteria (Bacillus substilis NCTC 10073, Staphylococcus aureus ATCC 25923, Enterococcus faecalis ATCC 29212, Bacillus thuringiensis ATCC 13838) and two Gram-negative bacteria (Pseudomonas aeruginosa ATCC 4853, Proteus vulgaris ATCC 4175) and a clinical isolate of Candida albicans.Results: CLE was active against all test organisms with minimum inhibitory concentration (MIC), range of 0.5 to 7.0 mg/mL against Gram-positive bacteria, 2.5 to 1.0 mg/mL against Gram-negative bacteria and 5.5mg/mL against C. albicans. The MICs of the methanol fraction of CLE were 0.6 mg to 5.0/mL and 1.0 to 3.0 mg/mL for Gram-positive and Gram-negative bacteria respectively. Chloroform fraction had MIC of 3.0 to 7.5 mg/mL and 2.0 to 6.5 mg/mL for Gram-positive and Gram-negative bacteria, respectively and petroleum ether fraction had 4.5 to 8.0 mg/mL for Gram-positive and Gram-negative bacteria. The CLE exhibited static action against all test organisms within a range of 0.5 to 22.0 mg/mL. Phytochemical screening of C. anisata revealed the presence of tannins, flavonoids, steroids, saponins, glycosides and alkaloids. HPLC finger-printing of the CLE and its fractions were determined.Conclusion: These results may justify the medicinal uses of C. anisata for the treatment of microbial infections.Keywords: Phytochemical screening, antibacterial, antifungal, static action
Etiology in 16 cases of toxic epidermal necrolysis and Stevens-Johnson syndrome admitted within 8 months in a teaching hospital
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Can the Hospital Anxiety and Depression (HAD) Scale be used on Chinese elderly in general practice?
A study was carried out in a general practice in Hong Kong to find out if the Hospital Anxiety and Depression (HAD) Scale could be used to detect psychological problems in Chinese elderly. The HAD Scale was translated into Cantonese and administered by an interviewer to 298 Chinese aged 60 or above before their doctor consultations. The acceptance rate of the Scale was 96% and each interview took only 5-10 min to complete. All 298 elderly understood and completed the HAD Scale. Validation of the results of the HAD Scale by the Clinical Interview Schedule (CIS) was done on a random sample of 100 elderly. Relative operating characteristic (ROC) analysis showed that the optimal cut-off points of the HAD Scale was a depression score of 6 and an anxiety score of 3. The sensitivity was 80%, specificity was 90%, OMR (overall misclassification rate) was 12%, positive predictive value was 67% and negative predictive value was 95%. Thirty-six per cent of the,elderly had scores above these cut-off points. More females than males had high anxiety scores. Nearly half of those with positive HAD scores were not known to have any psychological illness. The HAD Scale has great potential to be used as a screening instrument for psychological illnesses in Cantonese-speaking Chinese elderly all over the world.postprin
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