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1.
In this study, we report on the cell adhesion properties of marrow stromal cells to extracellular matrix components such as collagen and noncollagenous proteins. The osteoblastic cells and their non-osteoblastic counter-parts (MBA series) from the marrow stroma differentially recognized a spectrum of extracellular matrix proteins. The osteoblastic cells, MBA-15, preferentially attached to bone matrix proteins, whereas fibroendothelial MBA-2.1 and adipocytic 14F1.1 cells did not. The MBA-15 cells demonstrated a preference in their attachment to fibronectin > mixture of collagens > bone matrix extracts > collagen type I > noncollagenous proteins. Clonal subpopulations derived from the MBA-15 cell line representing various stages along the osteogenic lineage expressed differential attachment preference. MBA-15.4, a less differentiated clonal line, was compared to MBA-15.6, a mature cell line.  相似文献   

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STUDY OBJECTIVE: To determine whether placing price labels on the vial caps of muscle relaxants increases cost consciousness among anesthesiologists. DESIGN: Retrospective study. SETTING: University hospital departments of anesthesia and pharmacy. MEASUREMENTS AND MAIN RESULTS: We placed price labels on the vial caps of all muscle relaxants for a study period of 1 year. At the beginning of the investigation, we informed the anesthesiologists of the study, discussed the prices for different muscle relaxants, and encouraged utilizing less expensive muscle relaxants whenever possible without compromising patient care. The price labels on the vial caps served as visual reminders of the various costs of muscle relaxants during daily practice. We compared the total amount spent on each muscle relaxant during the period from October 1993 to September 1994 with the period from October 1994 to September 1995. The total number of surgical cases from October 1993 to September 1994 and from October 1994 to September 1995 was unchanged and equaled 20,389 and 20,358 cases, respectively. Expenditures for pancuronium increased 104.1%. Total expenditure decreased by 12.5%, with a net savings of $47,111. CONCLUSION: Expenditures for the less costly pancuronium increased while expenditures for vecuronium and atracurium decreased. Price labeling of muscle relaxants in conjunction with education reduces total pharmacy expenditure on muscle relaxants.  相似文献   

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Acrylonitrile (ACN) produces tumors in rats, particularly gliomas of the brain, but tests for genotoxicity have yielded mixed results and no ACN-DNA adducts have been identified in the brain. To examine the possibility that ACN-related brain tumors were not a consequence of binding of ACN to brain DNA, experiments were conducted to investigate possible epigenetic mechanisms. Male Sprague-Dawley rats were exposed to 0, 3, 30, and 300 ppm ACN in drinking water for 21 days, a range that includes doses associated with brain tumorigenesis. In the 30 and 300 ppm ACN groups, 8-oxodeoxyguanosine (8-oxodG) levels were two fold greater than in the controls. Measures of glutathione levels, glutathione peroxidase and catalase were not significantly changed, but cyst(e)ine was somewhat increased. No changes were found in brain cytochrome oxidase activity, which indicates a lack of metabolic hypoxia. Also, no effects on thiobarbituric acid reactive substances were found, indicating a lack of lipid peroxidation. In an additional experiment, male Sprague-Dawley rats were exposed to 0 or 100 ppm ACN in drinking water for 94 days; interim sacrifices were conducted at 3, 10, and 31 days. Levels of brain nuclear DNA 8-oxodG were significantly increased in ACN-exposed rats compared with controls. Another group of animals were given weekly i.v. injections of 5 mg/kg methylnitrosurea and no increases in 8-oxodG were found. These studies suggest the possibility that ACN-induced tumors may be produced by a mode of action involving 8-oxodG. The formation of 8-oxodG is not understood, but does not appear to involve lipid peroxidation or disruption of antioxidant defenses.  相似文献   

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This paper describes the design of a novel ultrasonic therapy system dedicated to the breast cancer treatment and the theoretical investigation of the heating characteristics of the system. The applicator is a cylinder comprised of a stack of rings. Each ring has up to 48 transducers mounted on the inside of the ring and directed towards the centre. The transducers operate in one of two frequency bands (1.8-2.8 MHz and 4.3-40.8 MHz), arranged alternately in each ring. During treatment the patient is positioned in prone position, with the breast immersed in water and surrounded by this array. This design was modelled and optimized by 3-D simulations for a variety of treatment conditions. The simulated results demonstrate that the system has an excellent capability to achieve and maintain a temperature distribution (41.5-44 degrees C) in a quadrant to a whole breast. Initial experiments using a single ring of transducers has been performed to verify the power deposition calculation.  相似文献   

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BACKGROUND: We studied the associations between c-erbB-2 protein overexpression and p53 protein accumulation in benign breast tissue and the risk of subsequent breast cancer. METHODS: We conducted a case-control study nested within the cohort of 4888 women in the National Breast Screening Study (NBSS) who were diagnosed with benign breast disease during active follow-up. Case subjects were the women who subsequently developed breast cancer (ductal carcinoma in situ [DCIS] or invasive carcinoma). Control subjects were matched to each case subject on NBSS study arm, screening center, year of birth, and age at diagnosis of benign breast disease. Histologic sections of benign and cancerous breast tissues were analyzed immunohistochemically. Information on potential confounding factors was obtained by use of a self-administered lifestyle questionnaire. RESULTS: Accumulation of p53 protein was associated with an increased risk of progression to breast cancer (adjusted odds ratio [OR] = 2.55; 95% confidence interval [CI] = 1.01-6.40), whereas c-erbB-2 protein overexpression was not (adjusted OR = 0.65; 95% CI = 0.27-1.53). The findings for c-erbB-2 and p53 did not differ among strata defined by menopausal status, allocation within the NBSS, history of breast disease, and whether the benign breast disease was detected at a scheduled screen or between screens. The results were also similar after exclusion of case subjects whose diagnosis of breast cancer occurred within 1 year of their diagnosis of benign breast disease and after exclusion of subjects with DCIS. CONCLUSIONS: p53 protein accumulation, but not c-erbB-2 protein overexpression, appears to be associated with an increased risk of progression to breast cancer in women with benign breast disease.  相似文献   

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In addition to left ventricular pump failure and low cardiac output, structural and metabolic alterations of skeletal muscle are thought to contribute to exercise intolerance seen in patients with CHF. Studies using cardiac myocytes have implicated nitric oxide elaborated by inducible nitric oxide synthase (iNOS) as a potential agent associated with the genesis of dilated cardiomyopathy. The present study was designed to locate iNOS in the working skeletal muscle of patients with congestive heart failure. Specific antibodies were used to detect iNOS by immunohistochemistry in skeletal muscle biopsies (m. vastus lateralis) of 37 patients with left ventricular pump failure and 8 normal controls. The expression was restricted to skeletal muscle myocytes and was increased five- to ninefold in patients with chronic heart failure. There was no statistically significant difference in iNOS expression between patients with dilated cardiomyopathy and those with ischemic cardiomyopathy. The finding of a locally increased expression of iNOS and the experimental evidence that NO attenuates the contractile performance of the skeletal muscle suggest that the expression of iNOS may be responsible for the exercise intolerance seen in patients with chronic heart failure.  相似文献   

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We previously reported that corymine, an alkaloidal compound extracted from the leaves of Hunteria zeylanica native to Thailand, potentiated convulsions induced by either picrotoxin or strychnine. Therefore, to clarify the mechanism of action of corymine, the effects of corymine on gamma-aminobutyric acid (GABA) and glycine receptors were examined. We used Xenopus oocytes expressing these receptors and the two-electrode voltage-clamp method. The receptors expressed in oocytes injected with rat brain and spinal cord RNA showed the pharmacological properties of GABAA and glycine receptors, respectively. Corymine (1-100 microM) partially (20-30%) reduced the GABA responses in oocytes injected with rat brain RNA, while marked (up to 80%) dose-dependent reductions were observed in the glycine responses in oocytes injected with rat spinal cord RNA. These observations suggest that corymine was more effective against the glycine receptors than the GABA receptors. The ED50 of corymine on the glycine response was 10.8 microM. Corymine, at 30 microM, caused a shift to the right, with a lower maximal response, of the glycine concentration-response curve. This indicated that the action of corymine on glycine receptors is neither competitive nor purely non-competitive. These observations suggest that a binding site other than the glycine recognition site of the glycine receptors is the site of action of corymine.  相似文献   

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Alcohol dependence has been described as a relapsing condition and it has been proposed that alcohol lapses could potentially be explained by dynamic associations between contextual, interpersonal, and intrapersonal risk factors. Yet, few studies have tested the associations between risk factors in the prediction of lapse dynamics. The current study was a secondary analysis of data from the COMBINE study (n = 1,383; COMBINE Study Research Group, 2003). The goal of the current study was to examine static (alcohol dependence severity, treatment history, marital status, psychiatric symptoms) and dynamic (negative affect, craving, stress) predictors of heavy drinking during the course of treatment and up to one year following treatment. Results from dynamic latent difference score models indicated that higher levels of static and dynamic risk and increased dynamic risk over time were significantly associated with greater increases in heavy drinking. Likewise, more frequent heavy drinking and higher static risk predicted higher levels of dynamic risk. In addition, changes in dynamic risk factors significantly mediated the association between changes in heavy drinking and both psychiatric symptoms and treatment history. It is important to note that while the effects of static and dynamic risk factors in the prediction of heavy drinking were statistically significant, the magnitude of the effects were small. The current study provided partial support for a dynamic model of relapse; however future research using intensive longitudinal data collection and more advanced statistical techniques could further elucidate lapse dynamics and potentially improve relapse prevention planning. (PsycINFO Database Record (c) 2011 APA, all rights reserved)  相似文献   

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Glomerella graminicola transformants were generated by insertional plasmid mutagenesis. Five transformants with developmental mutant phenotypes that segregated in crosses as single-gene mutations were selected. In four transformants, the mutant phenotype cosegregated with the inserted plasmid DNA. At least three of the mutants result from gene disruption, as demonstrated by recovery of the mutant phenotypes after transformation of wild type with "rescued" plasmid DNA. Whereas the wild type produces uninucleate, salmon-colored conidia, the tagged mutant M26 has white conidia. After exposure to either UV light or singlet oxygen, the percentage germination of M26 conidia is reduced compared to that of the wild-type conidia, indicating that the spore pigment confers protection from UV light and singlet oxygen. The tagged mutant T30 has weakened walls; falcate conidia rupture and hyphae have swollen regions unless the medium is amended with an osmoticum. The tagged mutant T29 has falcate conidia with one to four nuclei; wild-type falcate conidia are uninucleate. Two other mutants, one which grows slowly and one having conidia with increased curvature, are also described.  相似文献   

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21 years after radiotherapy for breast cancer, a 63-year-old woman developed a malignant mesenchymoma of the chest wall. The total irradiation dose was 132 Gy. The first clinical symptom of this second malignancy was a slight irregular calcification around the implanted silicon protheses observed in a conventional chest X-ray. Radiation-induced sarcoma is a very rare complication of radiotherapy. In cases of chest wall calcification after radiation therapy further investigation should be carried out, because some patients with radiation-induced sarcoma could be saved, if an early diagnosis is reached.  相似文献   

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We describe a patient with dysfunction of a Medtronic Hall prosthetic valve showing peculiar patterns of aortic regurgitation and carotid pulse caused by valvular thrombosis. The aortic regurgitation was considered to be caused by a significant delay in prosthetic valve closure, manifested by a peculiar regurgitation pattern limited to early diastole, in association with widely split closing clicks and an abnormally low dicrotic notch in the carotid pulse. At surgery, fibrin thrombi were noted just below the prosthetic ring in the minor outflow region which restricted disc movement. The fibrin thrombi were removed and the valve was rotated 90 degrees. Following reoperation, all abnormalities disappeared.  相似文献   

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A hypertensive 72-year-old male presented with a ruptured arteriovenous malformation (AVM) manifesting as hematoma indistinguishable from common putaminal hemorrhage on precontrast computed tomography scan. The AVM was located in the proximal sylvian region fed by branches of the anterior and middle cerebral arteries. The AVM was totally removed. Although bleeding from AVM in the elderly is uncommon, the cause of even common hypertensive hemorrhage should be identified by other imaging techniques such as magnetic resonance imaging and cerebral angiography to allow the optimum treatment.  相似文献   

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Allergic reactions during or after dental examination are uncommon. However, such reactions may be serious and distressing. Allergy to local anaesthetics and dental materials may be considered, but reactions to rubber in gloves worn by the dentist should be remembered. Two patients are reported who experienced symptoms following contact with rubber gloves worn by their dentists, with skin tests subsequently showing an allergic reaction to glove constituents, and in one case latex. With the increasing use of rubber gloves by dental and medical personnel, reactions in sensitised patients are likely to become more common. In patients with a history of symptoms related to dental work, it is important to remember delayed and immediate reactions to rubber.  相似文献   

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PURPOSE: We evaluated whether the results of transurethral microwave thermotherapy improve using high intraprostatic temperatures of 55C or greater. MATERIALS AND METHODS: We accrued 30 men 58 to 85 years old (mean age 69) from the waiting list for transurethral prostatic resection in whom maximum urinary flow was less than 13 ml. per second and Madsen score was greater than 8. According to the Abrams-Griffith nomogram all but 1 patient had obstruction. Before treatment 3 thin temperature probes, each containing 5 sensors in a row, were introduced into the prostate from the perineum and positioned using transurethral ultrasound guidance. The microwave power of the transurethral microwave thermotherapy equipment was set based on the actual temperature in the prostatic tissue. A temperature of at least 55C and often more than 60C was reached at the hottest spot. Treatment duration was 1 hour. Postoperatively an indwelling catheter remained in place for 2 weeks. Patients were followed for 6 months with the first followup after 3 months. RESULTS: At the 3-month followup mean maximum urinary flow had increased from 7.4 to 12.5 ml. per second and the mean Madsen score had decreased from 12.6 to 2.9. At the 6-month followup mean maximum urinary flow was 12.2 ml. per second and the mean Madsen score was 3.4. Using pressure-flow data we divided the patients into responders and nonresponders. In the 18 responders maximum urinary flow had increased from 7.2 to 14.6 ml. per second (103%), the Madsen score had decreased from 12.5 to 1.4 (89%) and detrusor pressure had decreased from 9.2 to 6 kPa. (35%). CONCLUSIONS: High energy transurethral microwave thermotherapy relieved bladder outlet obstruction in 60% of the patients and had a good effect on symptoms. Compared with a previous multicenter study with 40% responders, using the same criteria there were 60% responders in our series. Our results indicate that better control of intraprostatic temperature provides better results, approaching those after transurethral prostatic resection.  相似文献   

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