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61.
D Robinette S Wada T Arroll MG Levy WL Miller EJ Noga 《Canadian Metallurgical Quarterly》1998,54(5):467-475
BACKGROUND: A major reduction in the energy demand of the myocardium results from the electromechanical arrest, and cooling contributes to a lesser degree to this reduction. It is from this assumption that strategies of myocardial protection, utilizing warm blood cardioplegic induction, followed by cold cardioplegia with terminal warm reperfusion before removal of the aortic cross clamp, became established as optimal myocardial protection. Continuous normothermic perfusion 'closed the loop' by avoiding myocardial ischemia and linking warm induction and terminal reperfusion. A series of laboratory and clinical data confirmed the benefits of warm heart surgery on myocardial function and metabolism. The disadvantages of continuous warm blood cardioplegia including disturbance of the operative field, led surgeons to administer warm hyperkalaemic blood intermittently as a new cardioplegic strategy. METHODS: This review examines the laboratory and clinical data with reference to the intermittent warm blood cardioplegia, to establish its experimental basis and place in clinical practice. CONCLUSIONS: Experimental observation and clinical application have established intermittent warm blood cardioplegia as a practical, effective and cheap myocardial protection technique, particularly with reference to coronary artery surgery. 相似文献
62.
SE Santos AK Ribeiro-Dos-Santos JF Guerreiro EJ Santos TA Weimer SM Callegari-Jacques MA Mestriner MH Franco MH Hutz FM Salzano 《Canadian Metallurgical Quarterly》1998,25(6):505-522
A total of 732 individuals affiliated with six Amazonian Indian populations were variously studied in relation to 26 protein genetic systems. Eleven of them were found to be monomorphic in these groups, in accordance with previous investigations. Similarities and dissimilarities (the latter involving the Rh, Duffy, haptoglobin and transferrin systems) were observed in relation to earlier investigations in four of these populations (Galibi, Palikour, Mundurucu and Tenharim). A dimeric, cathodal variant of albumin was found among two Galibi subjects, and the fairly common occurrence of CP* ACAY among some South American Indian populations was confirmed. The results in the six populations were compared with those from 29 others. When relationships are searched for among tribes of the same linguistic group, the factor that seems to be most influential is geographical localization, an exception being the pattern observed among the Cayapo subgroups. The latter shows genetic differences of the same level of magnitude as those observed among Ge-speaking tribes. 相似文献
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EJ Lee YC Hung CH Chang MC Pai HH Chen 《Canadian Metallurgical Quarterly》1998,140(6):599-604; discussion 604-5
The purpose of this study was to evaluate pre- and post-shunting haemodynamic changes and their correlation with the clinical results in normal pressure hydrocephalus (NPH). Accordingly, eleven demented patients with clinical signs suggestive of NPH received examinations of cerebral blood flow velocity (BFV) and vasomotor reactivity (VMR) by transcranial Doppler sonography with carbogen testing before and after shunt treatment. Computerized tomography (CT), clinical assessment and neuropsychological grading were performed prior to and at 3 months following surgery. A control group consisting of 10 patients was included to establish baseline data. The pre-operative CBF studies in the anterior cerebral artery (ACA) and the middle cerebral artery (MCA) revealed the NPH patients did not have significant decreases of BFVs, but had significant decreases of carbogen VMR (P < 0.05). After shunting, there were no significant changes of the BFVs as compared with the pre-shunting data. The post-shunting VMR of the ACA was significantly higher than the pre-shunting one (p < 0.05), but there was no variation in that of the MCA. Both the values of post-shunting VMR in ACA and the post-shunting increase in VMR in MCA of the 7 shunt-responsive patients who improved mentally and in other symptoms were significantly higher than those of patients without improvement (p < 0.05). In addition, the five patients with gait improvement showed significantly higher values of post-shunting VMR of ACA and the post-shunting increase of VMR for both ACA and MCA when compared with those patients without gait improvement (p < 0.05, respectively). Our study supports the view that patients with NPH had various degrees of impaired VMR in both the ACA and the MCA, but showed insignificant reduction in BFVs, indicating a compensatory mechanism of CBF over time to accommodate the subnormal state of cerebral perfusion pressure. Shunt placement would improve the VMR in responsive patients. Postoperatively, an increase of VMR tends to accompany improvement of the functional state: that in the MCA alone is associated with symptomatic improvement in mental function and that increase in VMR in both the ACA and the MCA with improvement in gait, respectively. 相似文献
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67.
W Temple J Toews H Fidler JM Lockyer P Taenzer EJ Parboosingh 《Canadian Metallurgical Quarterly》1998,41(6):439-445
PURPOSE: To describe adolescents' and young adults' knowledge about their health insurance, and to identify factors associated with correct knowledge of health insurance in this population. METHODS: Data were analyzed from a confidential questionnaire administered to 830 patients at a hospital-based adolescent medicine clinic. The questionnaire contained items pertaining to insurance type, demographics, health status, and health-risk behaviors. Actual health insurance data and information regarding utilization of health services were obtained from the hospital billing data-base. Predictors of health insurance knowledge were determined through bivariate analyses followed by stepwise logistic regression. RESULTS: A total of 50.7% of respondents correctly identified their type of health insurance. Those who correctly identified their insurance had a higher mean age. Only 48.5% of participants who were 11-18 years old could identify their insurance type, versus 53.1% of 19-21-year-olds and 64.7% of 22-24-year-olds (p = 0.02). Sixty-five percent of Medicaid patients and 76.3% of hospital free care patients knew how their medical bills were paid, versus 17.9% of self-pay patients and 47.3% of patients with private insurance (p < 0.01). Greater utilization of health services was associated with increased rates of insurance knowledge among 19-24-year-olds on bivariate analysis; however, this factor was not significant when controlling for other factors. Regression analysis revealed that older age and insurance type other than self-payment were independent predictors of health insurance knowledge in adolescents (11-18 years old), while female gender and insurance type other than self-payment were independent predictors of insurance knowledge in young adults (19-24 years old). CONCLUSIONS: Approximately half of adolescents and young adults do not know how their medical bills are paid. Validation of self-reported insurance data is, therefore, critical both in clinical practice and health services research. 相似文献
68.
Non-invasive evaluation of gastric emptying is generally performed by scintigraphy which is, however, not always applicable and is not suitable for children and child-bearing women. Recently, a new method based on stable isotope breath testing has been introduced in clinical practice i.e., the 13C-octanoic acid breath test. An overview is made here of the current knowledge on this technique with special emphasis on the principle of the test, the mathematics used to analyse the results, and the physiological, pathological, and pharmacological aspects of gastric emptying studied with this new method. Possible pitfalls of the test are also reported. 相似文献
69.
We combined histofluorescence with in situ hybridization to identify GABAergic neurons in the arcuate nucleus (ARC) following electrophysiological recordings, using GAD65 as a marker. Intracellular recordings were made in hypothalamic slices prepared from ovariectomized guinea pigs. Over 90% of ARC neurons tested with the GABA(B) receptor agonist baclofen responded with a membrane hyperpolarization or an outward current. The hyperpolarization was dose-dependent, and the GABA(B) receptor antagonist CGP 35,348 produced a rightward shift in the agonist dose-response curve. Agonist potency was lower, and the efficacy greater, in GAD-positive neurons. The use of this novel technique for identifying GABAergic neurons thus reveals differences in the pharmacodynamics of GABA(B) receptor activation GABAergic and non-GABAergic ARC neurons. 相似文献
70.