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91.
Voice recognition is an exciting technology that is only starting to catch on in radiology. By reducing training time from days to several minutes, today's voice recognition systems are more practical than their predecessors. Voice recognition systems will improve the productivity of radiologists, allowing them to spend less time dictating their findings and more time concentrating on their specialty. Ultimately, the major benefit is increased patient care. As more and more hospitals become automated, voice recognition systems are a natural fit in this process. Radiology departments will be able to have integrated systems that will allow everything from initial patient entry, procedure status and tracking, and report dictation with voice recognition, to electronic report signature, report archiving, and patient billing.  相似文献   
92.
For patients with an oversized inferior vena cava (IVC) (diameter greater than 28 mm, corrected for magnification) who require vena caval filtration for prophylaxis against pulmonary emboli, the accepted treatment has been the biiliac venous placement of Greenfield filters. Because of its wide strut span, the Bird's Nest filter (BNF) has been successfully placed in patients having an oversized IVC. However, the effects of the BNF on caval blood flow and its clot-capturing ability in an oversized IVC are not clearly understood. The authors created a flow phantom simulating an oversized IVC with "iliac" tributaries of normal inner diameter to analyze flow turbulence, pressure gradients, and the clot-capturing ability of the BNF, tested within the "caval" segment of the phantom, and the Greenfield, Vena Tech-LGM, and Simon nitinol filters, tested in the "iliac" segments. All filters were tested for flow disturbances before and after clot capture. The authors' results demonstrate that within an oversized IVC, the BNF creates less flow disturbance and is less occlusive with clot capture than biiliac filters. The BNF displayed a clot-capturing ability equal to that of biiliac filters. Thus, for patients with an oversized IVC, these results suggest that placement of a single intracaval BNF is preferable to biiliac placement of filters.  相似文献   
93.
Hyaluronan (HYA) is an important structural element in skin and is presumably participating in regulation of the interstitial fluid volume. HYA is transported via the lymphatics from the tissues to the blood, where its concentration is normally very low. Fluid flux through the interstitium is markedly increased after thermal injury. The present study was performed to determine whether major thermal injury would affect plasma levels of HYA. In halothane-anesthetized sheep subjected to 40% BSA full-thickness scald burns, plasma HYA concentration increased from 116 +/- 19 (mean +/- SEM) to 172 +/- 18 ng/ml within 1 hr after injury (P less than 0.05). After 3 hr of fluid therapy plasma HYA concentration was further elevated to 10 times baseline (1417 +/- 322 ng/ml) (P less than 0.01). To clarify whether this rise represented an increased "washout" of interstitial HYA, attributable either to the burn injury or the subsequent fluid therapy, awake sheep were subjected to overhydration. Following a 3-hr infusion of lactated Ringer's 2.5 liter/hr, plasma HYA concentration increased to 2-3 times baseline. Lung lymph flow and its concentration of HYA increased, leading to an increase in the lymphatic flux of HYA to 10-20 times baseline. In peripheral lymph HYA flux increased 2-3 times baseline. Infusion of lactated Ringer's markedly increased lymphatic removal of HYA. However, plasma concentrations of HYA were 3 times higher after thermal injury than following fluid challenge alone, suggesting that thermal injury per se may also increase input of HYA into the systemic circulation.  相似文献   
94.
Isolated rat liver hepatocytes, previously depleted of glutathione(GSH) by treatment with diethylmaleate, were allowed to incorporate[3H]glycine into their GSH. Incubation of 3H-labelled cellswith 14C-labelled (±)-trans-7,8-dihydroxy-7,8-dihydrobenzo[a]pyrene((±)-BP-7,8-dihydrodiol) or (±)7ß,8-dihydroxy-9,10-epoxy-7,8,9,10-tetrahydrobenzo[a]-pyrene(()-BPDE) revealed the formation of double labelled products.This together with evidence from amino acid analysis indicatesformation of GSH-conjugates of the highly carcinogenic BP-derivatives.Incubation of hepatocytes isolated from 3-methylcholanthrene(MC) treated rats with 3H-labelled (±)-BP-7,8-dihydrodiolor (±)-BPDE resulted in binding of radioactivity to DNA.Reduction of the intracellular level of GSH to 40% of the normallevel resulted in an approximate 2-fold increase in the DNA-bindingof either substrate. In addition there was a concurrent decreasein the amount of GSH-conjugates formed. These data clearly demonstratethat GSH participates in conjugation reactions with carcinogenic(±)-BP-7,8-dihydrodiol and (±)-BPDE and that theintracelluilar level of GSH is important in preventing reactiveintermediates from reacting with the DNA in intact cells.  相似文献   
95.
Neurotropic melanoma. A variant of desmoplastic melanoma   总被引:14,自引:0,他引:14  
We report a group of neuroid, cutaneous tumors that are usually associated with, or preceded by a melanocytic dysplasia. For this clinicopathologic entity we have chosen the term neurotropic melanoma. The neurotropic melanoma is a cutaneous fibrous tumor whose clinical course is characterized by local infiltration, multiple recurrences, and commonly by metastases. Its microscopic picture is characterized by atypical "neuroma-like" patterns, by poorly defined margins, and by neurotropism. Its early or precursory melanocytic dysplasias include lentigo maligna (actinic or lentigo maligna variant), and a melanoma with borderline cytologic characteristics (minimal deviation variant). A third type is not preceded by a recognizable melanocytic dysplasia: it has "neuroma-like" qualities at its inception (de novo variant). In our 22 cases, the preponderant sites were the head, neck, and lip. The patients were fair-faced, and 18 of the patients were over 40 years old. Seventeen patients had one or more recurrences. Of 16 patients with follow-up, nine died with evidence of disease, five are alive with active disease, and seven are apparently free of disease.  相似文献   
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98.
PURPOSE: Rituximab has clinical activity in patients with chronic lymphocytic leukemia (CLL) and has a variety of proposed mechanisms, including apoptosis, complement-dependent cell lysis (CDC), and antibody-dependent cellular cytotoxicity (ADCC). Here we examine pretreatment biologic features that promote resistance to apoptosis and CDC in CLL patients and correlate it with clinical outcome to rituximab-based therapy. PATIENTS AND METHODS: Pretreatment samples from 21 CLL patients treated on a prospective, single-agent rituximab trial were examined for quantitative expression of apoptotic and CDC regulatory proteins, and the level of expression of these proteins was correlated with clinical outcome. RESULTS: Of the 21 patents for whom samples were available, 10 attained a partial response and 11 failed to respond to rituximab therapy. The mean pretreatment expression of Bcl-2, Mcl-1, XIAP, and the ratio of Bcl-2/Bax were higher but not statistically increased in nonresponding patients versus those responding to treatment. In contrast, the pretreatment Mcl-1/Bax ratio was significantly elevated (0.82 +/- 0.28 v 0.39 +/- 0.29, P <.016) in nonresponding patients compared with patients responding to rituximab therapy. Although pretreatment expression of CD55 and CD59 was not associated with response to rituximab therapy, significantly higher levels of CD59 were observed in the CLL cells that were not cleared from the blood at completion of therapy than the level observed at baseline levels (P =.02). CONCLUSION: These data indicate that baseline expression of the Mcl-1/Bax ratio, but not CD55 and CD59, predict for clinical response to rituximab therapy in CLL patients. Further study of disrupted apoptosis in CLL as a potential mechanism of resistance to rituximab appears warranted.  相似文献   
99.
Traumatic brain injury (TBI) increases susceptibility to Alzheimer's disease (AD), but it is not known if TBI affects the progression of AD. To address this question, we studied the neuropathological consequences of TBI in transgenic (TG) mice with a mutant human Abeta precursor protein (APP) mini-gene driven by a platelet-derived (PD) growth factor promoter resulting in overexpression of mutant APP (V717F), elevated brain Abeta levels, and AD-like amyloidosis. Since brain Abeta deposits first appear in 6-month-old TG (PDAPP) mice and accumulate with age, 2-year-old PDAPP and wild-type (WT) mice were subjected to controlled cortical impact (CCI) TBI or sham treatment. At 1, 9, and 16 weeks after TBI, neuron loss, gliosis, and atrophy were most prominent near the CCI site in PDAPP and WT mice. However, there also was a remarkable regression in the Abeta amyloid plaque burden in the hippocampus ipsilateral to TBI compared to the contralateral hippocampus of the PDAPP mice by 16 weeks postinjury. Thus, these data suggest that previously accumulated Abeta plaques resulting from progressive amyloidosis in the AD brain also may be reversible.  相似文献   
100.
Several studies have found that smoking cigarettes is a risk factor for systemic lupus erythematosus (SLE). To examine this issue in a mouse model, we subjected pre-autoimmune MRL-lpr/lpr mice for 4 weeks to cigarette smoke to provide standardized smoke effluents equivalent to moderate or to heavy smoking habits for people. The spontaneous production of IgG anti-chromatin but not IgM anti-chromatin, anti-denatured DNA, or rheumatoid factor antibodies was lower in mice exposed to 250 mg/m3 particulates from mainstream smoke, and this suppression of autoimmunity was sustained for 8 weeks (p < 0.02). In contrast to control mice anti-chromatin activity in smoke-exposed mice began to increase in 16-week-old mice, reaching levels at 6 months that were two- to three-fold higher than controls for IgG (p < 0.03) and 10-fold higher for IgM (p < 0.001). There was no significant effect on total IgG or IgM. In newly diagnosed SLE patients, smoking was negatively correlated with IgG anti-DNA antibodies (p < 0.03). However, of nine patients who discontinued smoking prior to diagnosis, eight had elevated IgG anti-DNA compared to 29/79 never smokers and 9/31 smokers (p < 0.01 compared to former smokers). Inhaled cigarette smoke appears to have a long-lasting immunosuppressive effect on T-cell-dependent autoimmune responses, although autoantibodies increase to supra-elevated levels after the suppressive effect has abated.  相似文献   
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