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31.
32.
Malignant cells within solid tumors commonly exhibit phenotypic changes such as alterations in karyotype and acquisition of the ability to invade and to metastasize. We have used a fibrosarcoma, grown subcutaneously in C57BL/6 mice, to study the mechanisms underlying this phenotypic instability. Tumor-bearing animals were injected with phorbol myristate acetate (PMA) and then the tumors were transplanted to animals without further PMA treatment. These tumor cells were tum+, that is, unlike the parental tumors, they were able to grow in animals immunized against the parental tumors. This property was maintained for at least 6 tumor passages after the initial PMA injections. Thus, PMA appears to be able to induce an unstable tum+ phenotype in these cells at relatively high frequency. 相似文献
33.
Several recent studies have reported conflicting results on the effectiveness of danazol, an attenuated androgen, in raising plasma levels of clotting factors VIII and IX in patients with hemophilia. We undertook a randomized, double-blind cross-over trial using 8 weeks' administration of danazol (D), 600 mg/d, and 8 weeks' administration of placebo (P) separated by 2 weeks of rest in 12 patients with hemophilia A and four patients with hemophilia B. Plasma factor VIII and IX levels, frequency and type of bleeding episodes, amount of factor concentrate infused, fibrinogen, fibrinolysis assays, antithrombin III, liver function, and immune parameters were followed. During the danazol phase a minimal increase was noted in the average clotting factor levels, an increase that, although statistically significant, was of hemostatically marginal magnitude. Significant increases in protein C and plasminogen levels, however, were observed during the danazol period, suggestive of danazol-mediated enhanced fibrinolysis. Clinically, bleeding frequency was significantly increased, and more clotting factor was consumed during the danazol period. Furthermore, eight episodes of hematuria and oral mucosal bleeding was reported during the danazol phase in contrast to only one episode of hematuria during the placebo phase, consistent with an enhancement of fibrinolytic activity with danazol. We conclude that danazol does not have a hemostatically significant effect on plasma levels of factor VIII and IX but may be associated with enhancement of fibrinolytic activity, resulting in increased bleeding frequency and requiring more clotting factor infusions. Therefore, danazol is not a viable alternative in the treatment of hemophilia. 相似文献
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35.
Jaundice develops in many patients with liver metastases from colorectal adenocarcinoma during hepatic arterial infusion chemotherapy (HAIC). The usual cause is thought to be hepatotoxicity from the chemotherapeutic agent or biliary obstruction from progressive neoplastic disease. The authors evaluated the abdominal computed tomography and ultrasound examinations performed on 49 patients who were jaundiced during long-term HAIC. In only one patient was diffuse intrahepatic biliary dilatation caused by an obstructing mass in the porta. Two patients had metastatic hepatic lesions causing focal biliary obstruction. Intrahepatic dilatation without an obstructing mass occurred in 20 patients. Percutaneous or endoscopic cholangiograms were commonly interpreted prospectively as showing extrinsic compression by metastases, but no mass was confirmed on imaging studies. Seven patients had focal intrahepatic ductal dilatation from stricture without an associated mass. The remaining 19 patients had normal-caliber ducts; their jaundice was caused by chemical hepatitis. This series suggests that the most common causes of jaundice in these patients are chemical hepatitis and common bile duct stricture, complications of intraarterial chemotherapy, rather than neoplastic obstruction. Stricture formation may be confused with extrinsic compression on direct cholangiograms. 相似文献
36.
Arteriovenous malformations of the extremities: MR imaging 总被引:3,自引:0,他引:3
Eight patients with angiographically proved arteriovenous malformations (AVMs) of the extremities (seven congenital, one posttraumatic) were evaluated with magnetic resonance (MR) imaging using a 0.35-T superconducting system and spin-echo pulse sequences. Congenital AVMs appeared as accumulations of dilated tortuous blood vessels infiltrating the involved muscles. A posttraumatic acquired AVM of the shoulder consisted of a large feeding artery associated with a pseudoaneurysm and a soft-tissue mass. MR imaging allowed precise anatomic localization and provided details concerning the size and extent of the AVMs. The relationship of AVMs to specific muscle groups, bones, and vascular structures could be accurately determined. Although major feeding and draining vessels were identified, the exact arteries and veins supplying and draining the AVM could not be ascertained. Images obtained in the transverse plane consistently yielded the most useful information. MR imaging and angiography may be complementary techniques in the initial evaluation, follow-up, and treatment planning of AVMs of the extremities. 相似文献
37.
Low-dose ibuprofen in self-medication of mild to moderate headache: a comparison with acetylsalicylic acid and placebo 总被引:4,自引:0,他引:4
A double-blind, threefold crossover, double-dummy trial was performed, investigating the efficacy of 200 mg ibuprofen compared with 500 mg acetylsalicylic acid and placebo in patients who usually treated their headaches with over-the-counter drugs. Ninety-five patients suffering from mild to moderate migraine or episodic tension-type headache were included. Seventy-seven patients entered the intention-to-treat analysis and 65 completed all three treatments. For the main response criterion, a minimum 50% decrease of headache intensity on a visual analogue scale at I h after treatment, ibuprofen was significantly superior to acetylsalicylic acid and placebo. This was true for migraine attacks and tension-type headache episodes. Towards the end of the observation period (150 min), the differences between ibuprofen and acetylsalicylic acid were no longer significant. In conclusion, ibuprofen was at least equivalent to acetylsalicylic acid and superior to placebo. 相似文献
38.
包膜活性炭吸附血液灌流清除人血浆中毒鼠强的实验 总被引:1,自引:0,他引:1
目的:观察包膜活性炭对血浆中毒鼠强的清除率及吸附规律。方法:实验于2004-05/2006-04在军事医学科学院毒物药物研究所国家重点实验室完成。采用包膜活性炭灌流器对毒鼠强血浆样进行血液灌流吸附,在灌流的1,2,3h分别取样,经乙酸乙酯萃取后,用气相色谱氮磷检测器法(GC/NPD)测定其含量并计算清除率。结果:活性炭对毒鼠强的吸附作用在血液灌流1h最高,灌流2h后毒鼠强质量浓度无明显变化。400,200μg/L毒鼠强血液灌流1h清除率分别为(57.83±1.85)%,(48.18±1.81)%。结论:用包膜活性炭吸附剂进行血浆的灌流吸附,能清除大部分毒物,迅速降低血浆中毒鼠强的质量浓度。 相似文献
39.
Autologous blood donors (ABDs) have been reported to have favorable attitudes toward returning as homologous blood donors (HBDs), but the frequency of return has not been well documented. ABDs eligible by history to be HBDs were followed at one blood center: 255 donating for elective surgery and 234 donating during pregnancy were followed for an average of 18 months and 20 months, respectively, from time of eligibility after surgery or postpartum. Male ABDs had a higher rate of return as HBDs, as 34 percent (21/62) returned to donate an average of 3 units, whereas 13 percent (56/427) of female ABDs returned as HBDs to donate an average of 2 units. Although a history of donation was associated with a higher rate of return (30%, 34/113), 11 percent (43/376) of ABDs with no history as HBDs returned to donate homologous units, despite having been recruited less frequently than prior HBDs. Overall, all male ABDs and female ABDs with an HBD history returned most frequently. The extra effort required for an autologous donor program may result in the recruitment of new donors into the HBD pool. 相似文献
40.
Sensitization of trigeminal nociception specific for migraine but not pain of sinusitis. 总被引:1,自引:0,他引:1
Neurology. 2002;59:1450-1453.
Trigeminal pain processing was studied in 14 patients with unilateral migraine attacks and 14 age- and sex-matched patients with comparable unilateral headache from frontal sinusitis. Using a nociception-specific blink reflex method (nBR), a facilitation of nBR responses predominantly on the headache side was observed in migraine, but not in sinusitis. The facilitation of trigeminal nociception may be specific for migraine rather than a consequence of peripheral pain such as frontal sinusitis.
Comment: Here we have evidence for the central hyperexcitability of migraine, not found in the previously cited article by Boska et al. SJT 相似文献
Trigeminal pain processing was studied in 14 patients with unilateral migraine attacks and 14 age- and sex-matched patients with comparable unilateral headache from frontal sinusitis. Using a nociception-specific blink reflex method (nBR), a facilitation of nBR responses predominantly on the headache side was observed in migraine, but not in sinusitis. The facilitation of trigeminal nociception may be specific for migraine rather than a consequence of peripheral pain such as frontal sinusitis.
Comment: Here we have evidence for the central hyperexcitability of migraine, not found in the previously cited article by Boska et al. SJT 相似文献