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11.
BACKGROUND: Aneurysmal degeneration of a carotid reconstruction was not recognized until the patient, who was known to have recurrent carotid artery stenosis, had a thromboembolic stroke. This sequelae of carotid endarterectomy is a serious complication, associated with a high morbidity and mortality rate. This review was conducted to establish the risk of transient ischemic attack and stroke for patients found to have recurrent carotid stenosis associated with aneurysmal degeneration of the carotid artery after endarterectomy. METHODS: A case is reported, and 100 literature references of aneurysmal degeneration of the carotid artery after endarterectomy were reviewed. RESULTS: False aneurysm from anastomotic disruption was the most common presentation identified in the cases reviewed. Nineteen of the patients had a significant neurologic event; however, three (50%) of six patients with aneurysm and recurrent carotid artery stenosis had a transient ischemic attack or stroke. CONCLUSIONS: The incidence of neurologic symptoms is markedly increased when recurrent carotid artery stenosis is associated with carotid aneurysm. During postoperative surveillance after endarterectomy, the identification of recurrent carotid artery stenosis requires evaluation for aneurysmal degeneration of the carotid artery with duplex scanning. These patients are at significant risk for transient ischemic attack and stroke. This rare complication merits operative repair. 相似文献
12.
A novel pathway of polycyclic aromatic hydrocarbon (PAH) metabolism involves the oxidation of non-K-region trans-dihydrodiols by dihydrodiol dehydrogenase (DD) to yield PAH o-quinones whose cytotoxicity and genotoxicity are unknown. The cytotoxicity of several PAH o-quinones derived from this reaction [naphthalene-1,2-dione (NPQ), benzo[a]pyrene-7,8-dione (BPQ), and 7,12-dimethylbenz[a]anthracene-3,4-dione (DMBAQ)] was examined in rat (H-4IIe) and human (Hep-G2) hepatoma cells which are known to express DD. 2-Methylnaphthalene-1,4-dione (menadione), a known cytotoxic p-quinone, was used as a positive control. Hepatoma cells (1 x 10(6) cells/mL) were exposed to PAH o-quinones (1-100 microM) for 0-4 h, and cell viability and survival were measured and related to O2.- production and changes in redox potential [GSSG/GSH and NAD(P)+/NAD(P)H]. Three different modes of cytotoxicity were observed: (1) NPQ (no bay region) and DMBAQ (methylated bay region) were as cytotoxic as menadione in reducing cell survival but had less effect on cell viability. These o-quinones adversely affected GSH levels and the redox state of the cell and caused an increase in the production of O2.- in cell suspensions. This cytotoxicity was not enhanced by dicoumarol (10 microM), a DT-diaphorase inhibitor, implying that this enzyme is unable to prevent these PAH o-quinones from entering one-electron redox-cycles. (2) BPQ (bay region only) was the least cytotoxic of the PAH o-quinones studied. BPQ decreased cell viability (< 40% at 20 microM) but did not adversely affect cell survival or the redox state of the cell.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
13.
Lactate clearance and survival following injury 总被引:1,自引:0,他引:1
D Abramson TM Scalea R Hitchcock SZ Trooskin SM Henry J Greenspan 《Canadian Metallurgical Quarterly》1993,35(4):584-8; discussion 588-9
Previous reports cite optimization of O2 delivery (DO2) to 660 mL/min/m2, O2 consumption (VO2) to 170 mL/min/m2, and cardiac index (CI) of 4.5 L/min as predicting survival. We prospectively evaluated 76 consecutive patients with multiple trauma admitted directly to the ICU from the operating room or emergency department. Patients had serum lactate levels and oxygen transport measured on ICU admission and at 8, 16, 24, 36, and 48 hours. Patients were analyzed with respect to survival (S) versus nonsurvival (NS), lactate clearance to normal (< or = 2 mmol/L) by 24 and 48 hours, hemodynamic optimization as defined above, as well as Injury Severity Score (ISS), ICU stay (LOS), and admission blood pressure. All patients achieved non-flow-dependent VO2. There was no difference in CI, DO2, VO2, or ISS when S was compared with NS. All 27 patients whose lactate level normalized in 24 hours survived. If lactate levels cleared to normal between 24 and 48 hours, the survival rate was 75%. Only 3 of the 22 patients who did not clear their lactate level to normal by 48 hours survived. Ten of the 25 nonsurvivors (40%) achieved the above arbitrary optimization criteria. Fifteen of the survivors never achieved any of these criteria. Optimization alone does not predict survival. However, the time needed to normalize serum lactate levels is an important prognostic factor for survival in severely injured patients. 相似文献
14.
Urinary tract infections (UTIs) are common conditions in clinical practice. For uncomplicated UTIs, the causative organisms and their antimicrobial susceptibility profiles are generally predictable, and empiric short course (3 day) antibiotic therapy after an abbreviated laboratory workup is advocated. Acute pyelonephritis requires a 2 week antibiotic course, often with initial parenteral therapy. Women with frequent recurrences of UTIs may require intermittent self-treatment or continuous or postcoital antibiotic prophylaxis. Catheter-associated UTIs generally only require treatment if the patient shows signs of systemic infection. Treatment of asymptomatic bacteriuria is only recommended in certain circumstances. Careful consideration of the clinical circumstances, the patient's known or predicted urinary tract anatomy, and the antibiotic susceptibility of the bacterial pathogen(s) are critical factors in the choice of appropriate therapy for urinary tract infections. 相似文献
15.
TM Drabkina DP Matyushkin VK Radzjukevich Romanovsky DYu 《Canadian Metallurgical Quarterly》1995,14(2):153-170
The effect of frog skeletal muscle incubate on fatigue was studied in frog sciatic nerve, sartorius muscle preparation. Fatigue was produced by prolonged repetitive (1 s-1) stimulation of motor nerve or of curarized muscle. The incubate partially restored isometric contraction amplitudes of muscle fatigued by nerve stimulation. This effect of partial recovery from fatigue (PRF effect) was exerted mainly by a relatively low-molecular fraction (LMF; < 10 kDa) of the incubate. The incubate and its fractions failed to produce the PRF effect in experiments with directly stimulated muscle. The action of LMF on synaptic transmission in unfatigued cutaneous-pectoris muscle was examined using binomial analysis of quantal transmitter release. LMF produced an increase in the end-plate potential quantal content (m) at synapses with low initial m values. In contrast, it produced a decrease i n m at synapses with higher m values. Both effects were due to respective changes in binomial parameter n. It is assumed that the stimulatory presynaptic action of the incubate on synapses the effectiveness of which was lowered during fatigue, could account for the PRF effect. A possible contribution of low- and high-molecular components of the incubate is discussed. 相似文献
16.
TM Munger DL Packer SC Hammill BJ Feldman KR Bailey DJ Ballard DR Holmes BJ Gersh 《Canadian Metallurgical Quarterly》1993,87(3):866-873
BACKGROUND: Virtually all natural history studies of Wolff-Parkinson-White (WPW) syndrome have been case series and, as such, have been constrained by referral biases, skewed age and sex distributions, or brief follow-up periods. The purpose of our study was to examine the natural history, the development of arrhythmias, and the incidence of sudden death in an entire cohort of pediatric and adult WPW patients from a community-based local population. METHODS AND RESULTS: We identified 113 residents of Olmsted County, Minnesota, during the period 1953-1989 using the centralized records-linkage system provided by the Mayo Clinic and the Rochester Epidemiology Program Project. Medical records and ECGs were reviewed to confirm the diagnosis and to establish pathway location by ECG criteria. Follow-up, via record review and telephone interview, was complete in 95% of subjects through 1990. The incidence of newly diagnosed cases was approximately four per 100,000 per year. Preexcitation was not present on the initial ECG of 22% of the cohort. Approximately 50% of the population was asymptomatic at diagnosis, with 30% subsequently having symptoms related to arrhythmia at follow-up. Two sudden cardiac deaths (SCD) occurred over 1,338 patient-years of follow-up, yielding an overall SCD rate of 0.0015 (95% confidence interval, 0.0002-0.0054) per patient-year. No SCD occurred in patients asymptomatic at diagnosis. CONCLUSIONS: The incidence of sudden death in a local community-based population is low and suggests that electrophysiological testing should not be performed routinely in asymptomatic patients with WPW syndrome. Nevertheless, young, asymptomatic patients, particularly those < 40 years old, should return for medical follow-up should symptoms develop. 相似文献
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BACKGROUND AND PURPOSE: We compared the results of conventional angiography, carotid Doppler, and magnetic resonance angiography volume flow rates to determine the clinical utility of volume flow rate assessment of blood flow to the anterior circulation in patients with carotid occlusive disease. METHODS: From 11 symptomatic patients, a total of 22 extracranial carotid arteries were studied with all three techniques. The studies were independently read, and regression analysis was used to compare the measurements. RESULTS: Carotid Doppler measurements of the distal extracranial carotid arteries were proportional to the inverse of the extracranial carotid volume flow rate (r = .53, R2 = 29%, P < .01), volume flow rates were proportional to the inverse of measured percent stenosis on angiography (r = .84, R2 = 71%, P < .01), and Dopplers were proportional to angiography (r = .94, R2 = 90%, P < .01). Symptomatic Doppler systolic velocity was significantly higher (P < .002), symptomatic measured stenosis was significantly higher (P < .002), and symptomatic volume flow rate was significantly lower (P < .01) than their respective asymptomatic-side values. These preliminary observations, however, may well change once a large data set, especially one in which more patients with high-grade carotid stenosis are included, is studied. CONCLUSIONS: Assessment of carotid volume flow rates by magnetic resonance angiography quantifies flow reduction secondary to atherosclerotic occlusive disease. The easily obtained flow data add both documentation of arterial flow characteristics related to internal carotid stenosis and information regarding the adequacy of collateral pathways. 相似文献