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991.
JJ Reina Zoilo M Ruiz Borrego JC Valenzuela Claros MJ Valladares Ayerbes P Borrega García A Viana Alonso JA Moreno Nogueira 《Canadian Metallurgical Quarterly》1998,15(2):97-99
Photosensitive epilepsy is relatively rare. However, a large proportion of individuals with epilepsy perceive that they are at an increased risk of a seizure whilst exposed to specific photic material. The difference between perceived and real risk may be due to inadequate education and misinformation. One half of the participants in the present survey could not recall being informed of the result of the 'gold standard' test for photosensitivity--intermittent photic stimulation during an electroencephalogram. Furthermore, approximately one-third of our sample were apparently given inaccurate and overcautious advice about their everyday exposure to photic material. Better information and advice is crucial to improve this situation in the future. The majority of people with epilepsy (>95%) who are not photosensitive can pursue activities that involve flickering or patterned light, encompassing educational, employment and leisure opportunities, without undue concern. 相似文献
992.
Alaska, with less than one-half of 1% of the United States workforce, accounts for 9% of all occupational aviation fatalities nationally; 30% of all occupational fatalities in Alaska are related to aviation. To understand this high mortality, we investigated occupational aviation crashes to identify risk factors. Occupational aviation fatalities in Alaska during 1990-94 were examined using National Transportation Safety Board reports and merged with records from the Alaska Occupational Injury Surveillance System. There were 876 aircraft crashes; 407 (46%) were work-related. Occupational crashes were 2.2 times (CI: 1.5, 3.2) more likely to result in fatalities than non-occupational crashes. Risk factors identified included poor weather conditions defined as Instrument Meteorological Conditions (IMC). A crash during IMC was 5.3 times (CI: 3.5, 7.9) more likely to result in fatalities than crashes in other conditions. Of aircraft involved in fatal occupational incidents, 33% were not completely destroyed, allowing the potential for survivors. An estimated 30% reduction in fatalities could have occurred if current technology in occupant protection had been used. 相似文献
993.
N Nassar GR Hoffman D Manor JC Clardy RA Cerione 《Canadian Metallurgical Quarterly》1998,5(12):1047-1052
The Rho-related small GTP-binding protein Cdc42 has a low intrinsic GTPase activity that is significantly enhanced by its specific GTPase-activating protein, Cdc42GAP. In this report, we present the tertiary structure for the aluminum fluoride-promoted complex between Cdc42 and a catalytically active domain of Cdc42GAP as well as the complex between Cdc42 and the catalytically compromised Cdc42GAP(R305A) mutant. These structures, which mimic the transition state for the GTP hydrolytic reaction, show the presence of an AIF3 molecule, as was seen for the corresponding Ras-p120RasGAP complex, but in contrast to what has been reported for the Rho-Cdc42GAP complex or for heterotrimeric G protein alpha subunits, where AIF4- was observed. The Cdc42GAP stabilizes both the switch I and switch II domains of Cdc42 and contributes a highly conserved arginine (Arg 305) to the active site. Comparison of the structures for the wild type and mutant Cdc42GAP complexes provides important insights into the GAP-catalyzed GTP hydrolytic reaction. 相似文献
994.
A Csendes P Burdiles JC Diaz F Maluenda O Korn E Vallejo P Csendes 《Canadian Metallurgical Quarterly》1998,45(23):1415-1421
BACKGROUND/AIMS: To determine if the use of Intraoperative choliangiography (IOC) should be routinely performed and, if not, which criteria should be used to select patients requiring IOC during open or laparoscopic cholecystectomy. METHODOLOGY: 495 Patients with 1 or more gallstones were included in a two-year study. Twelve clinical, laboratory, ultrasonographic and intraoperative factors were chosen and evaluated in all cases. Prior to cholecystectomy, IOC was performed after having identified the common bile duct (CBD) and cystic duct. The majority of the patients were operated on by the same surgeon to avoid differences in criteria and techniques. Statistical evaluation made use of the exact Fisher test and chi square test and, a p-value less than 0.05 was considered as significant. RESULTS: IOC could be performed in 479 out of the 495 cases. IOC resulted in a normal CBD in 76.0%, had a false positive in 2.7%, a false negative in 0.48%, and a presence of 1 or more stones in the CBD in 20.9%. The study revealed that when none of the 12 risk factors were present, there were no cases with CBD stones. As the number of risk factors increased, so did the number of cases presenting with CBD stones. CONCLUSION: Not all 12 risk factors show the same index of predictability; only 5 in particular (jaundice, ultrasound diameter CBD 7 mm, bilirubin over 26 umol/it, cystic duct > 4 mm and CBI, diameter over 9 mm) showed a high rate of predictability. However, when careful measurement and evaluation of risk factors for CBD stones are undertaken, it is possible to avoid the routine use of IOC. 相似文献
995.
G Haddock AP Morrison R Hopkins S Lewis N Tarrier 《Canadian Metallurgical Quarterly》1998,172(33):101-106
BACKGROUND: Cognitive-behavioural treatments have previously been explored in the treatment of chronic psychotic problems, but recently, the effectiveness of these treatments has been investigated with regard to recent onset and acute psychosis. METHOD: The literature relating to cognitive-behavioural treatments in psychosis is explored and the application of the approach to recent onset psychosis is described in detail. RESULTS: There appears to be a growing body of evidence that the advances made in the treatment of people with chronic treatment resistant psychosis can be similarly applied to people with recent onset and acute psychosis. CONCLUSIONS: Cognitive-behavioural treatments are feasible with recent onset psychotic patients although further evaluation of their effectiveness is necessary. 相似文献
996.
Vasculitis can affect every organ of the digestive system. In many cases, it may first present with gastrointestinal symptoms. In several forms of vasculitis, including Churg Strauss syndrome, Henoch-Sch?nlein purpura, and lupus, the majority of patients have gastrointestinal involvement. The astute gastroenterologist should consider vasculitic causes of the symptoms seen in many patients. Making the correct diagnosis requires a thorough understanding of the potential role of vasculitis in causing these symptoms and the appropriate path to making a diagnosis. This article reviews the variety of manifestations of vasculitis on the digestive system, and emphasizes diagnosis and clinical manifestations. 相似文献
997.
F Haeseleer J Huang L Lebioda JC Saari K Palczewski 《Canadian Metallurgical Quarterly》1998,273(34):21790-21799
The reduction of all-trans-retinal in photoreceptor outer segments is the first step in the regeneration of bleached visual pigments. We report here the cloning of a dehydrogenase, retSDR1, that belongs to the short-chain dehydrogenase/reductase superfamily and localizes predominantly in cone photoreceptors. retSDR1 expressed in insect cells displayed substrate specificities of the photoreceptor all-trans-retinol dehydrogenase. Homology modeling of retSDR1 using the carbonyl reductase structure as a scaffold predicted a classical Rossmann fold for the nucleotide binding, and an N-terminal extension that could facilitate binding of the enzyme to the cell membranes. The presence of retSDR1 in a subset of inner retinal neurons and in other tissues suggests that the enzyme may also be involved in retinol metabolism outside of photoreceptors. 相似文献
998.
BJ Tolkamp I Kyriazakis JD Oldham M Lewis RJ Dewhurst JR Newbold 《Canadian Metallurgical Quarterly》1998,81(10):2670-2680
Diet choice, expressed as grams of high protein feed selected per kilogram of intake, was measured for lactating cows with ad libitum access to two feeds. First, cows were given a choice between a low protein feed and a high protein feed for 9 wk while feeds were alternated between feeders. The proportion of feed chosen from a feeder depended on the feed it contained, which showed that cows selected for feed characteristics. Diet choice was then measured over six periods during which cows had access to either a low protein feed and a high protein feed or to these feeds plus added urea. Diet choice was lower when urea was added, suggesting a substantial effect of the content of ruminally degradable protein (RDP) in feeds on diet selection. All feeds had equal RDP contents in Experiment 3 when early and late lactating cows had access first to two feeds with a low and high yield of metabolizable protein and then to two feeds with a low and medium yield of metabolizable protein. Diet choice did not differ from what was considered to be random and was not affected by milk yield or stage of lactation. No evidence suggests that cows selected for metabolizable protein when both feeds contained adequate RDP. 相似文献
999.
JC Corvol C Oppenheim R Mana? M Logak D Dormont Y Samson C Marsault G Rancurel 《Canadian Metallurgical Quarterly》1998,29(12):2649-2652
BACKGROUND: Diffusion-weighted imaging (DWI) is the most sensitive MR sequence in acute arterial ischemic stroke but has not yet been evaluated in venous cerebral ischemia. We describe a patient with DWI performed at the acute phase of a venous ischemic stroke. CASE DESCRIPTION: A rapid cerebral MRI including DWI and fast fluid-attenuated inversion recovery (FLAIR) sequences was performed at the acute phase of a venous stroke confirmed by conventional angiography. DWI showed a slight decrease in apparent diffusion coefficient values 3 hours after onset (0.53+/-0.07x10(-3) mm2/s) and was normal 48 hours later (0.064+/-0.15x10(-3) mm2/s). Fast FLAIR sequences showed large left frontoparietal hyperintensities. The lack of a clear decrease in apparent diffusion coefficient values associated with marked FLAIR abnormalities may suggest prominent or early associated vasogenic edema. Physiopathological differences between arterial and venous ischemia may explain the different type of DWI FLAIR abnormalities during the acute phase as well as the better recovery of neurological deficit in venous stroke than in arterial ischemic stroke. CONCLUSIONS: In the context of an acute stroke, the contrast between marked FLAIR and subtle DWI abnormalities on MRI may reflect the venous mechanism of cerebral ischemia. 相似文献
1000.
MR Sapoval BM Beyssen C Girardot MA Musset P Legmann O Brekke JC Gaux 《Canadian Metallurgical Quarterly》1996,51(3):210-213
In the past, interleukin-8 (IL-8) could be demonstrated within keratinocytes in normal epidermis and inflammatory skin diseases, like psoriasis and eczema. Using monoclonal antibodies, the distribution of IL-8 immunoreactivity was inversely related to the density of inflammatory infiltrate. Other in vitro observations indicated IL-8 to be a growth factor for keratinocytes. These results prompted an immunohistochemical examination of IL-8 immunoreactivity in malignant and semimalignant epithelial tumours of human skin. Whereas IL-8 could not be detected within the transformed cells of epithelial tumours or melanoma, some tumour cells within well differentiated squamous cell carcinoma and Bowen's disease showed IL-8 immunoreactivity. Thus, loss of IL-8 immunoreactivity can be a sign of malignant transformation. This indicates an important role in growth regulation as well as terminal differentiation of human keratinocytes. 相似文献