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121.
WE Johnston PG Robertie JF Butterworth RL Royster ND Kon 《Canadian Metallurgical Quarterly》1992,6(5):528-534
To determine whether ephedrine or CaCl2 improves hemodynamics in cardiac surgery patients emerging from cardiopulmonary bypass, three sequential doses of either CaCl2 (200 mg/dose; n = 12), ephedrine (5 mg/dose; n = 12), or placebo (n = 12) were administered in a prospective, randomized, double-blind fashion. Thermodilution volumetric catheters were used to calculate right ventricular (RV) volumes and ejection fraction. The first dose of ephedrine improved RV stroke volume from 57 +/- 3 to 63 +/- 4 mL/beat (P < 0.05) and ejection fraction from 44 +/- 2% to 49 +/- 2% (P < 0.05). Subsequent doses maintained this improvement but without further change. In contrast, placebo and CaCl2 had minimal effects on RV end-systolic volume, stroke volume, and ejection fraction. After the third injection of ephedrine, mean arterial pressure had significantly increased from 78 +/- 2 to 93 +/- 4 mmHg (P < 0.05) in contrast to insignificant increments with placebo and CaCl2. Serum ionized calcium increased by 6% to 8% after each CaCl2 bolus but remained stable in the ephedrine and placebo groups. CaCl2 failed to improve RV performance in mildly hypocalcemic patients during separation from cardiopulmonary bypass. In patients with normal preoperative ventricular function, ephedrine more effectively improved RV performance and arterial blood pressure than placebo or CaCl2, and is a suitable short-acting drug to assist separation from cardiopulmonary bypass. 相似文献
122.
Preliminary experience with medical applications of rapid prototyping by selective laser sintering 总被引:3,自引:0,他引:3
E Berry JM Brown M Connell CM Craven ND Efford A Radjenovic MA Smith 《Canadian Metallurgical Quarterly》1997,19(1):90-96
Rapid prototyping techniques, originally developed for building components from computer aided designs in the motor industry, are now being applied in medicine to build models of human anatomy from high resolution multiplanar imaging data such a computed tomography (CT). The established technique of stereolithography and the more recent selective laser sintering (SLS), both build up an object layer by layer. Models have applications in surgical planning, for the design of customised implants and for training. Preliminary experience of using the SLS technique for medical applications is described, addressing questions regarding image processing, data transfer and manufacture. Pilot models, built from nylon, included two skills (a child with craniosynoslosis and an adult with hypertetorism) and a normal femur which was modelled for use in a bioengineering test of an artificial hip. The dimensions of the models were found to be in good agreement with the CT data from which they were built-for the child's skull the difference between the model and the CT data was less than 1.0 +/- 0.5 mm in each direction. Our experience showed that, with care, a combination of existing software packages may be used for data conversion. Ideally, image data of high spatial resolution should be used. The pilot models generated sufficient clinical interest for the technique to be pursued in the orthopaedic field. 相似文献
123.
GJ Wang ND Volkow JS Fowler NR Pappas CT Wong K Pascani CA Felder RJ Hitzemann 《Canadian Metallurgical Quarterly》1998,22(8):1850-1854
It is generally believed that women are more vulnerable to alcohol's toxic effects than men. Studies in male alcoholics have consistently shown reductions in brain glucose metabolism. However, such studies have not been done in female alcoholics. The purpose of this study was to evaluate if similar or worse brain metabolic abnormalities occurred in female alcoholics. For this purpose, we measured regional brain metabolism with positron emission tomography and [18F]fluorodeoxyglucose in 10 recently detoxified female alcoholics and compared it with that in 12 age-matched female controls. There were no differences between alcoholics and control females in regional brain glucose metabolism whether we used regions of interest analysis or statistical parameter maps methods. These results do not support a higher toxicity for the effects of alcohol in the female brain, as assessed with regional brain glucose metabolism, because metabolic values in female alcoholics did not differ from those of controls, whereas metabolic values in male alcoholics are generally lower than those in controls. However, this study is confounded by the fact that the severity of alcohol use in these female alcoholics was less than that of the male alcoholics previously investigated in positron emission tomography studies. Future studies in male subjects with alcoholism of moderate severity are required to address gender differences in sensitivity to alcohol effects in brain metabolism. 相似文献
124.
ND Khoroshko RA Mokeeva AG Turkina EA Semenova AV Pivnik 《Canadian Metallurgical Quarterly》1997,69(7):26-33
Clinical, hematological, cytogenetic and pathohistological findings in 14 patients with high eosinophilia allowed the authors to distinguish 2 groups of patients: with symptomatic (secondary) and idiopathic hypereosinophilic syndromes (6 and 8 patients, respectively). The latter was characterized by hepato- and splenomegaly, specific cardiac lesion (thromboplastic endocarditis), non-infectious fever, anemia and thrombocytopenia, marked hypercellularity of the bone marrow with inhibition of erythro- and megakaryocytopoiesis. Ph'-chromosome occurred in 2 out of 8 cases. Biopsy and autopsy histology in all cases of idiopathic hypereosinophilic syndrome were typical for myeloproliferative diseases. In symptomatic hypereosinophilic syndrome the above features were not registered. 相似文献
125.
AIM: To develop a reliable, machine-readable coding system for dental appliances. METHODS: Incorporation of two-dimensional bar codes and matrix codes into a range of dental appliances using printed thermal substrates and laser-etched ceramic discs. RESULTS: Problems including reaction of thermal substrates with methyl methacrylate monomer, loss of code clarity, limited areas available for bar codes, difficulty in scanning opaque pigmented acrylic resin and palatal and lingual surfaces were overcome using 4 mm2 data matrix codes etched onto ceramic discs. CONCLUSIONS: Reliable automatic identification of dental appliances was achieved using laser-etched matrix codes. Further development is necessary in relation to optimisation of code size, encryption, scanners and maintenance of code readability over time. 相似文献
126.
Acute inflammatory polyradiculitis represents an uncommon peripheral nerve complication during HIV infection. The case of an HIV-seropositive patient who was admitted to hospital for a cauda equina syndrome is reported. Despite early application of anticytomegalic medication, a cytomegalovrirus (CMV) infection spread out to the central nervous system (CNS), causing the patient's death. A post-mortem examination confirmed the diagnosis of CMV-encephalomyelomeningoradiculitis. To the authors' knowledge, such a progress of a CMV-related polyradiculitis to an encephalomyelomeningoradiculitis has not yet been described. The clinical features of this case will aid in the recognition of CMV-related neurological complications, and may permit earlier and perhaps more successful treatment. 相似文献
127.
AE Morgan SP Porter FA Clarkson ND Volkow JS Fowler SL Dewey 《Canadian Metallurgical Quarterly》1997,26(4):423-427
Small cell carcinoma of the larynx is an uncommon epithelial tumor, which is the most aggressive subtype of neuroendocrine carcinomas. Because of its nonspecific clinical and radiological manifestations, the diagnosis of small cell carcinoma of the larynx is essentially based on the light microscopic examination aided by electron microscopy or immunohistochemical staining. We report a case of supraglottic small cell carcinoma accompanied by large bilateral cervical lymph node metastasis ocurring in a 70-year-old man. On CT scans, no area of low attenuation indicating necrosis was demonstrated within such large metastatic lymph nodes. We suggest that small cell carcinoma of the larynx should be included in the diagnostic considerations when a laryngeal mass is accompanied by large cervical lymph nodes without necrosis shown by CT. 相似文献
128.
NIu Sakharova LN Markova KA Lepikhov ND Zvezdina GA Buznikov 《Canadian Metallurgical Quarterly》1997,28(2):125-131
Blood pressure (BP) during siesta declines to levels similar to those of night time sleep. The objective of the study was to assess the effect of siesta on 24-h ambulatory BP (ABP) data. Two different approaches were employed for the definition of day and night periods: (1) actual patient reported day and night intervals (ACT) with siesta period analysed as a third time period; and (2) arbitrary day and night time intervals (ARB) with the presence of siesta being ignored. A total of 203 24-h ABP recordings were analysed, with a siesta during ABP monitoring reported in 154 of them. Mean siesta BP was very close to ACT night time BP. Among recordings with a siesta, ACT daytime BP was higher and night time BP lower than the corresponding ARB BPs (P < 0.001). The magnitude of night time BP drop was greater with ACT intervals, resulting in a lower percentage of non-dippers (P < 0.001). Among 49 recordings without a siesta, differences between ACT and ARB BPs were less pronounced for daytime but not for night time. Differences in the magnitude of nocturnal BP drop between ACT and ARB periods, although statistically significant, did not affect the prevalence of non-dippers. In conclusion, analysis of 24-h BP profiles by using ARB instead of ACT day and night intervals results in underestimation of the nocturnal BP drop and overestimation of the proportion of non-dippers. This bias is more pronounced in patients who take a siesta during ABP monitoring. 相似文献
129.
130.