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991.
LJ Schlagel L Bors GW Mitchell JL King L Cao M Kirk JN Whitaker 《Canadian Metallurgical Quarterly》1997,34(2):185-194
We examined the effect of a nitric oxide (NO) quencher, stroma-free human hemoglobin A (HbA0; 0.01, 0.05, 0.1, 0.2 g/kg), on the blood flow measured using the Doppler flow technique, tumor oxygen pressure (pO2) and the diameter of the arterioles using R3230Ac mammary adenocarcinoma as the tumor model. In female Fischer 344 rats with 1-cm-diameter tumors implanted in the lateral aspect of the left quadriceps, intravenous infusion of 0.1 and 0.2 g/kg HbA0 decreased both central tumor and peripheral tumor blood flow by 20-30% (P < 0.05). Tumor pO2 decreased 28% with 0.2 g/kg HbA0, from 15 mm Hg (baseline) to 11 mm Hg at 10 min (P = 0.02). Although 0.2 g/kg HbA0 increased blood flow 55% in the left quadriceps muscle proximal to the implanted tumor (P < 0.05), HbA0 had little effect on blood flow in right quadriceps muscle with no tumor implanted, and increased right quadriceps pO2, from 21 mm Hg (baseline) to 23 mm Hg at 10 min (P = 0.03). HbA0 increased mean arterial pressure 5-10% in a manner that was dependent on dose while heart rate concurrently decreased 9-19%. The diameter of the arterioles supplying the tumor was rapidly reduced 10% by 0.2 g/kg HbA0 (P = 0.037) and remained stable through 60 min of observation (P = 0.005). HbA0 selectively reduces tumor blood flow and tumor pO2 through vasoconstriction of the arterioles supplying the tumor. Vascular NO quenching provides an alternative to NO synthase inhibition as a means to achieve the goal of selective tumor hypoxia. 相似文献
992.
993.
A major focus of the current health care debate is the notion that a substantial proportion of the health care delivered in Canada is inappropriate. There are two types of appropriateness: appropriateness of a service and appropriateness of the setting in which care is provided (i.e., inpatient v. outpatient or home care). Measuring both types objectively requires the comparison of observed patterns of care with explicit criteria for appropriate care. The few studies of appropriateness conducted in Canada have shown that inappropriate services are provided and inappropriate settings are used. Reducing inappropriate health care delivery could involve active strategies for the implementation of guidelines and better cooperation and coordination within the health care system. However, lower rates of health care delivery or even inappropriate health care will not necessarily translate into higher quality care or lower costs overall. 相似文献
994.
FH Takeda T Harashima JN Eto Y Kimura K Matsumoto 《Canadian Metallurgical Quarterly》1998,14(6):270-273
The purpose of the study was to assess the applicability of a new ITKA GSD Basic 250 electrosurgical unit (ESU) to urologic endoscopic surgery, laparoscopic surgery and open urologic surgery, its possible interference with videorecording and stray currents in healthy tissues. A new ITKA GSD Basic 250 ESU (test ESU) was used and compared to conventional ESU (Berchtold Elektrotom 390 as reference ESU). Experimental surgery was carried out on three female pigs, which underwent endoscopic, laparoscopic and open surgery. Altogether 29 patients underwent either endoscopic or open surgery with the test ESU. In experimental surgery, the ideal cutting and coagulation settings of the test ESU were in the range 15-25% for endoscopic surgery. In laparoscopic surgery, tissues were ideally resected and removed at 10-15% power settings. In open experimental surgery, the ideal power settings were 25-30%. In human surgery, the test ESU operated well at 25-35% power settings in endoscopic surgery, while in open surgery on humans the ideal settings were 25-35% in monopolar use and 20-25% in bipolar use. When used for endoscopic operations, the test ESU did not interfere with videorecording. Nor were any adverse effects seen in the surrounding tissues. The patients had neither early nor late complications. Histopathological findings revealed no differences in healing between the test ESU and reference ESU. Experimental and patient surgery showed the test ESU to be both safe and effective. It is suitable to be used in urologic endoscopic surgery, laparoscopic surgery and open urologic surgery. It does not interfere with videorecording or cause harmful stray currents in surrounding tissues. Power can be adjusted linearly and precisely. Low-power operation is also possible. 相似文献
995.
A transportation network is a complex system that exhibits the properties of self-organization and emergence. Previous research
in dynamics related to transportation networks focuses on traffic assignment or traffic management. This research concentrates
on the dynamics of the orientation of major roads in a network and abstractly models these dynamics to understand the basic
properties of transportation networks. A model is developed to capture the dynamics that leads to a hierarchical arrangement
of roads for a given network structure and land use distribution. Localized investment rules, wherein revenue produced by
traffic on a link is invested for that link's own development, are employed. Under reasonable parameters, these investment
rules, coupled with traveler behavior, and underlying network topology result in the emergence of a hierarchical pattern.
Hypothetical networks subject to certain conditions are tested with this model to explore their network properties. Though
hierarchies seem to be designed by planners and engineers, the results show that they are intrinsic properties of networks.
Also, the results show that roads, specific routes with continuous attributes, are emergent properties of transportation networks.
Received: April 2003 / Accepted: October 2004 相似文献
996.
The effects of olfactory bulbectomy (OBX) on galanin (GAL) gene expression in the locus coeruleus (LC) were examined with quantitative in situ hybridization histochemistry. OBX increased prepro-GAL levels 3 and 14 days after surgery, as compared to sham-operated controls. Levels of mRNA encoding prepro-neuropeptide Y (NPY) were unchanged, and levels of mRNA encoding tyrosine hydroxylase (TH) were elevated in the LC only on day 3. The results indicate that GAL gene expression in the LC increases after lesioning a terminal field. 相似文献
997.
998.
M Smith G Gettinby M Granstr?m JS Gray EC Guy C Revie JN Robertson G Stanek 《Canadian Metallurgical Quarterly》1998,287(3):266-269
We report a case of transient left lateral gaze paresis due to a hemorrhagic lesion restricted in the right precentral gyrus. A 74-year-old female experienced a sudden clumsiness of the left upper extremity. A neurological examination revealed a left central facial paresis, distal dominant muscle weakness in the left upper limb and left lateral gaze paresis. There were no other focal neurological signs. Laboratory data were all normal. Brain CTs and MRIs demonstrated a subcortical hematoma in the right precentral gyrus. The neurological symptoms and signs disappeared over seven days. A recent physiological study suggested that the human frontal eye field (FEF) is located in the posterior part of the middle frontal gyrus (Brodmann's area 8) and the precentral gyrus around the precentral sulcus. More recent studies stressed the role of the precentral sulcus and the precentral gyrus. Our case supports those physiological findings. The hematoma affected both the FEF and its underlying white matter in our case. We assume the lateral gaze paresis is attributable to the disruption of the fibers from the FEF. It is likely that fibers for motor control of the face, upper extremity, and lateral gaze lie adjacently in the subcortical area. 相似文献
999.
F Herencia ML Ferrándiz A Ubeda JN Domínguez JE Charris GM Lobo MJ Alcaraz 《Canadian Metallurgical Quarterly》1998,8(10):1169-1174
This is a report on the surgical intervention in 79 patients with acute pancreatitis, who were operated in the Department of Surgery of the University Clinic RWTH Aachen in the period from 1986 to 1993. The main objective was the stratification of pancreatitis according to the Ranson-Score, the analysis of the surgical treatment and the timing of operation depending on the clinical condition. The average Ranson-score was 3.3 (median 3). 56 patients had necroses, which were removed because of the deteriorating clinical condition. In these cases the average Ranson-score was 4.2 (median 4). Seven patients (8.9% of the total number and 12.5% of the patients with necroses of the pancreas) died. This small number is the result of a severity-adapted management in a modern intensive care-unit and the good cooperation with the Department of Internal Medicine. 相似文献
1000.
VP Kurup B Banerjee PS Murali PA Greenberger M Krishnan V Hari JN Fink 《Canadian Metallurgical Quarterly》1998,19(9):1469-1477
Aspergillus fumigatus ribotoxin Asp f 1 is a major allergen with IgE binding activity to serum of a majority of patients with allergic bronchopulmonary aspergillosis (ABPA). The IgE binding epitopes or the T-cell stimulatory peptides of this molecule have not been studied. In the present investigation, we have synthesized linear decapeptides spanning the whole molecule of Asp f 1 and analyzed their IgE binding properties. We have also synthesized peptides based on their possible T-cell stimulatory properties and studied the stimulation of peripheral blood mononuclear cells from ABPA patients and normal controls. Several peptides demonstrated distinct IgE antibody binding response against sera from ABPA patients and proliferative response against peripheral blood mononuclear cells from the patients. From the results, it can be concluded that the carboxy-terminal region of Asp f 1 representing amino acid residues 115-149 involved in both humoral and cell mediated immunoresponses in ABPA. 相似文献