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51.
Rosenson-Schloss RS Vitolo JL Moghe PV 《Medical & biological engineering & computing》1999,37(2):257-263
Leukocytes adherent to the surfaces of both vascular biomaterials and normal blood vessels experience blood flow induced shear stress. The goal of the reported studies was to investigate the effect of fluid flow on the morphology, phagocytic function and stress response induction in adherent immune cells. Shear approximating arterial, venous and intermediate levels were applied onto glass-adherent IC21 macrophages in a temperature-controlled parallel plate flow system. The results indicate that fluid flow induces a shear-dependent physiological stress response in adherent macrophages and that significant morphological changes accompany macrophage responses to shear stress. In addition, arterial flow conditions induce not only significant cell polarisation, but also enhanced phagocytic ingestion in glass-adherent IC21 macrophages. These findings suggest that blood flow induced shear stress may not only be consequent to adherent leukocyte activation, but may also be integral to the regulation of adherent leukocyte behaviour in vivo. 相似文献
52.
1993年7月~1998年1月为103例(106只眼)难治性青光眼患者施行国产房水引流物(HAD)置入术。术后平均随访328月。术后1年时平均眼压22±1.4kPa。术后1~5年的手术成功率分别为838%,804%,771%,710%及643%。术中联合应用丝裂霉素C的病例,其术后1年时的成功率为895%。术后常见的并发症有持续性浅前房,局限性脉络膜脱离及眼压升高等。认为HAD可用于治疗难治性青光眼。 相似文献
53.
AIM: To determine current clinical practice in the radiological diagnosis of acute pulmonary embolism and assess the use of spiral volumetric computed tomography. METHOD: A survey of 327 acute hospitals including cardiothoracic and orthopaedic tertiary referral centres was undertaken to assess current utilization of lung scintigraphy, spiral computed tomography and pulmonary angiography in the investigation of suspected pulmonary embolism. Responses were received from 215/327 (66%) centres. RESULTS: Lung scintigraphy was provided by 208 hospitals (144 on-site and 64 off-site). Spiral CT services were provided by 111 (52%) hospitals (on- or off-site), 142 (66%) units had access to angiographic facilities. Sixty-three centres out of 215 (29%) offered both on-site lung scintigraphy and spiral CT while only 41/215 (19%) hospitals were able to undertake all three tests on-site. On average, 501 perfusion (Q) or ventilation-perfusion (V/Q) scintigrams were performed per hospital per year with 26 spiral CT studies and just 4.6 pulmonary angiograms. CONCLUSION: These data suggest that lung scintigraphy is frequently the only imaging test in patients other than chest radiography, despite the large number of indeterminate results reported in most series. 相似文献
54.
Purpose. In a patient with internal derangement of the shoulder, the diagnostic method of choice is controversial. Conventional arthrography
can diagnose most rotator cuff tears accurately; however, in many institutions MR arthrography is usually necessary to diagnose
labral tears. We utilized decision tree methodology to compare the cost- effectiveness of conventional arthrography and conventional
MRI with a hypothetical algorithm in which a patient underwent arthrography, performed with admixed gadolinium, which if negative,
was followed by MRI.
Design. The use of double-contrast arthrography alone, conventional MRI alone, and gadolinium-enhanced MRI used as an adjunct to
conventional arthrography were modeled for the diagnosis of full-thickness rotator cuff tears (RCT), partial RCTs, labral
tears, and the absence of cuff/labral tears using decision analysis methodology. English language medical publications were
searched to determine the base probabilities for the accuracy of the diagnostic tests. The outcome utilities ranged from –1
to +1 to reflect the value of correct diagnostic evaluation. Charges for diagnostic tests and appropriate surgical treatments
were based on 1997 Medicare reimbursement rates for professional fees and hospital charges in an outpatient setting. Sensitivity
analyses were performed to evaluate the effects of uncertainty regarding the prevalence of each disease state and the accuracy
of several diagnostic tests.
Results. In the base-case analysis, the average effectiveness of double-contrast arthrography alone, MRI alone and arthrography selectively
followed by MRI were 0.6610, 0.6715, and 0.7204, respectively. The average costs for each of these strategies were $1090,
$2033, and $2339, respectively.
Conclusion. Arthrography performed with admixed diluted gadolinium, which if negative is immediately followed by MRI, was somewhat more
expensive than conventional MRI. However, because of much greater effectiveness, cost-effectiveness was significantly higher
for our proposed algorithm. Conventional arthrography without gadolinium, although less expensive, had severely limited effectiveness.
Received: 4 June 1999 Revision requested: 6 August 1999 Revision received: 30 August 1999 Accepted: 1 September 1999 相似文献
55.
In this study, thirty-eight patients with a variety of upper abdominal diseases were examined with three-dimensional time-resolved
MR angiography (7 sec/data set). Visualisation of arterial and venous anatomy was excellent in the majority of patients. Moreover,
subtraction images could be calculated and organ perfusion could be assessed. It is concluded that this technique opens new
perspectives for a comprehensive evaluation of vascular and parenchymal disease.
Received: 14 April 1998; Revision received: 23 October 1998; Accepted: 9 November 1998 相似文献
56.
An Unexpected Change in DXA Calibration not Detected by Routine Quality Control Checks 总被引:2,自引:0,他引:2
G. M. Blake N. G. Preston R. Patel R. J. M. Herd I. Fogelman 《Osteoporosis international》1999,9(2):115-120
Since its commercial introduction a decade ago, the technique of dual-energy X-ray absorptiometry (DXA) has been widely recognized
as a useful and sensitive method of measuring changes in bone mineral density (BMD) at selected sites in the skeleton such
as the spine and proximal femur. Because of their high precision and stable calibration, DXA scanners are frequently used
in clinical trials to evaluate new treatments for osteoporosis. Quality assurance procedures based on regular scanning of
phantoms are widely adopted in such trials, and continuity of the phantom BMD measurements is generally believed to ensure
continuity in the in-vivo calibration. We report a change in calibration of a DXA scanner that occurred during a clinical
trial where the calibration shift was different for the spine and femur sites and was not predicted or explained by the standard
quality control procedures using phantoms. However, we show that provided patients enrolled in studies are thoroughly randomized
and the statistical analysis is confined to the differences between the treated and control groups, then the effects of such
calibration shifts on conclusions regarding the efficacy of treatment are considerably smaller than the random statistical
errors.
Received: 12 February 1998 / Accepted: 20 May 1998 相似文献
57.
Dlugosz LJ Hocter WJ Kaiser KS Knoke JD Heller JM Hamid NA Reed RJ Kendler KS Gray GC 《Journal of clinical epidemiology》1999,52(12):90-1278
Effects of Persian Gulf War (August 2, 1990–July 31, 1991) and Gulf War occupation on post-War hospitalization risk were evaluated through Cox proportional hazards modeling. Active-duty men (n = 1,775,236) and women (n = 209,760) in the Army, Air Force, Navy, and Marine Corps had 30,539 initial postwar hospitalizations for mental disorders between June 1, 1991 and September 30, 1993. Principal diagnoses in the Defense Manpower Data Center hospitalization database were grouped into 10 categories of ICD-9-CM codes. Gulf War service was associated with significantly greater risk for acute reactions to stress and lower risk for personality disorders and adjustment reactions among men. Personnel who served in ground war support occupations (men and women) were at greater risk for postwar drug-related disorders. Men who served in ground war combat occupations were at higher risk for alcohol-related disorders. Longitudinal studies of health, hospitalization, and exposure beginning at recruitment, are needed to better understand how exposure to combat affects the mental health of military personnel. 相似文献
58.
Systemic lupus erythematosus 总被引:11,自引:0,他引:11
59.
C. M. Pacella Z. Rossi G. Bizzarri E. Papini V. Marinozzi D. Paliotta P. Castaldo V. Ziparo F. Garosi M. Cinti F. Muzzi 《European radiology》1993,3(1):26-32
The present report evaluates the efficacy and safety of percutaneous interstitial laser tissue ablation of the liver in nine New Zealand rabbits. A Nd: YAG laser was coupled to a quartz fibreoptic guide (600 m) with a flat tip. The fibre and a thermocouple were placed in the lumen of two Chiba needles (18G) and these were inserted into the liver 10 mm apart under ultrasound guidance. The laser was fired for 5 min at 1, 3 and 5 W power, respectively, in three groups of rabbits. There were no acute complications and all the rabbits except one survived until the established time of sacrifice. The procedure induced a cavity surrounded by a zone (about 10 mm) of coagulative necrosis. After 2 weeks a strong peripheral inflammatory response was evident and after 4 weeks a capsule of connective tissue enclosed the lesions. Our study seems to offer a safe and rapid technique producing a guaranteed kill radius for the treatment of small hepatic neoplasms.
Correspondence to: C. M. Pacella 相似文献
60.
Pollen JJ 《The Prostate》1980,1(2):251-258
This report reviews the roles of conventional radiography, computerized axial tomography, and nuclear bone scanning in the diagnosis, staging, follow-up, and management of prostatic cancer. Computed tomography (CT) offers great promise for the better definition of the extent of the primary tumor of prostatic cancer. It contributes positively to the planning of radiation therapy portals in the treatment of localized disease. By means of bipedal lymphangiography and CT scanning, pelvic and periaortic lymphadenopathy may be detected more often than was previously possible without staging pelvic lymphadenectomy, which can be reserved for the discovery of microscopic disease. Soft-tissue metastases that are located deep within the body cavities can now be measured accurately by CT scanning, as can their response to therapy. Skeletal metastases, the most common variety in prostatic cancer, can be detected with a high degree of sensitivity by nuclear bone imaging. Serial bone scans are remarkably useful in following the response of osseous deposits to treatment, as well as in detecting relapsing disease. The management of malignant obstruction of the ureters has been greatly facilitated by the application of angiographic techniques to percutaneous nephrostomy performed under fluoroscopic control. 相似文献