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排序方式: 共有195条查询结果,搜索用时 15 毫秒
61.
BACKGROUND & AIMS: The majority of patients with celiac sprue experience diarrhea before diagnosis. There have been no studies of the prevalence or causes of chronic diarrhea in these patients after treatment with a gluten-free diet. METHODS: Seventy-eight patients with celiac sprue (59 women and 19 men) treated with a gluten-free diet for at least 12 months were surveyed about their bowel habits. Those with chronic diarrhea, defined as passage of loose stools three or more times per week for 6 months, underwent an extensive diagnostic evaluation to determine its cause. RESULTS: Sixty-two of the 78 patients (79%) experienced diarrhea before treatment, and 13 (17%) had chronic diarrhea (of lesser severity) after treatment. The causes of diarrhea in 11 patients consenting to this study were microscopic colitis, steatorrhea secondary to exocrine pancreatic insufficiency, dietary lactose or fructose malabsorption, anal sphincter dysfunction causing fecal incontinence, and the irritable bowel syndrome. Only 1 patient had antigliadin antibodies detected in serum or small intestinal villous atrophy. CONCLUSIONS: After treatment of celiac sprue with a gluten-free diet, chronic diarrhea persists in a substantial percentage of patients. Although ongoing gluten ingestion is one possible cause, other causes may be more frequent. Therefore, diagnostic investigation of diarrhea in celiac sprue after treatment seems warranted. (Gastroenterology 1997 Jun;112(6):1830-8) 相似文献
62.
Enhanced transcription factor DNA binding and gene expression induced by arsenite or arsenate in renal slices 总被引:1,自引:4,他引:1
Although the kidney represents a target for the accumulation and toxicity
of arsenic, little is known about the molecular targets of arsenic in this
organ. Therefore, these studies were designed to examine the molecular
impact of arsenite [As(III)] and arsenate [As(V)] at low (nanomolar)
concentrations. Precision-cut rabbit renal cortical slices were challenged
with As(III) or As(V) for up to 8 h. Neither form of the metal induced
overt cytotoxicity as assessed by intracellular K+ levels over this time
period at concentrations from 0.01-10 microM. In addition, no alterations
in the expression of Hsp 60, 70, or 90 were observed. However, induction of
heme oxygenase-1 (Hsp 32) was seen following a 4-h challenge with As(III),
but not with As(V). As(III) and As(V) induced DNA binding of AP-1 at 2- and
4-h exposure; following a 6-h exposure there was no difference. Although no
alteration in the DNA binding activity of ATF-2 was induced by As(III) or
As(V), both forms enhanced the DNA binding activity of Elk-1. Enhanced DNA
binding activity of AP-1 and Elk-1 correlated with increased gene
expression of c-fos, but not c-jun, at 2 h. c-myc gene expression was also
induced by As(III) and As(V), albeit at a later time point (6 h). These
results suggest that acute arsenic challenge, by either As(III) or As(V),
is associated with discrete alterations in the activity of signaling
pathways and gene expression in renal tissue.
相似文献
63.
64.
Thrombolytic therapy with tissue plasminogen activator or streptokinase induces transient thrombin activity 总被引:7,自引:0,他引:7
We have determined the plasma level of fibrinopeptide A as a specific index of thrombin activity during the infusion of a thrombolytic agent in patients with acute myocardial infarction. Peripheral venous plasma levels of fibrinopeptide A increased following the initiation of thrombolytic therapy from 2.7 nmol/L to a peak of 13.0 nmol/L at 30 minutes with streptokinase and from 1.1 nmol/L to a peak of 10.7 nmol/L at 90 minutes with tissue plasminogen activator. The amount of fibrinogen converted to fibrin I was determined by integration of the plasma level of fibrinopeptide A over time. The amount of fibrin I formed over the five-hour period from the start of drug infusion was approximately 10 mg/dL in response to either streptokinase or recombinant tissue plasminogen activator. We conclude that activation of coagulation occurs in response to thrombolytic therapy despite heparin administration. This thrombin action, though transient, would be sufficient to cause rethrombosis if localized and incompletely opposed by fibrinolytic activity. 相似文献
65.
BACKGROUND: There is little information on the natural history of refractory gastric ulcer, defined as non-healing on cimetidine > or = 1 g daily given for at least 3 months. SETTING: A district general hospital serving an industrial population. METHODS: Patients with refractory gastric ulcer had their treatment extended and/or the dose increased, and upon healing the majority were put on maintenance treatment with cimetidine 400 mg nightly or 1 g daily and their progress was followed. RESULTS: Of 536 patients with gastric ulcer, 74 (14%) were refractory. Fifty of the 74 (68%) refractory gastric ulcer patients were refractory on their very first course of cimetidine. They had no distinguishing demographic features. Healing occurred in 62 patients (84%) after a mean treatment period of 11.1 months; 28 patients required cimetidine > or = 2 g daily. Eleven of 23 (48%) patients relapsed on maintenance with cimetidine 400 mg compared with seven of 24 (29%) on 1 g daily. A total of 22 out of 62 (35%) relapsed; nine had a second refractory recurrence but none thereafter. Eleven patients were operated upon, seven for failed medical treatment. Only two patients eventually proved to have malignant disease. CONCLUSIONS: Refractory gastric ulcer is uncommon, transient and rarely malignant. Most patients can be satisfactorily managed medically. 相似文献
66.
Brown SB; Hedlund GL; Glasier CM; Williams KD; Greenwood LH; Gilliland JD 《Radiology》1987,164(2):475-478
Four infants with congenital or acquired tracheobronchial stenosis were successfully treated with angioplasty balloon catheter dilation. The technical details and complications of these procedures are described. The authors believe balloon dilation therapy should be considered as the initial form of therapy for tracheal stenosis in infants, even in the presence of complex stenotic lesions. 相似文献
67.
68.
Mainstream oral care flavours are primarily designed to provide hedonic (taste) benefits and to promote breath freshness. In particular, a key criterion for a commercially successful toothpaste flavour is a long lasting reduction in the perception of mouth odour. Various additives can help deliver this benefit, in addition to flavours formulated according to patented guidelines. The residence time (substantivity) in the mouth of flavours and additives is clearly critical with respect to the longevity of the breath-freshening benefit, and little data are available in the literature to guide the selection of substantive components. The aim of this project was to investigate the dynamics of flavour loss from the buccal cavity following brushing using a mass spectrometer equipped with an atmospheric pressure headspace sampler which enabled real-time determination of flavour components in mouth air. A number of flavour ingredients found in peppermint- and spearmint-based oral care flavours were studied. The in vivo decay kinetics of flavour ingredient loss were quantified and found to be strongly related to the physicochemical properties of ingredients, except in the case of esters where a more complex dependence was observed arising from chemical transformation occurring in addition to physical transportation away from the mouth. Surprisingly, some materials were discovered to undergo rapid degradation with a half-life of minutes. Confirmatory studies of the decay kinetics of such materials were carried out in vitro, and structural features were identified which were associated with the observed hydrolytic vulnerability. This work has allowed the development of new guidelines to enable the creation of longer-lasting oral care flavours. 相似文献
69.
Localization of neuroendocrine tumours with [111In] DTPA-octreotide scintigraphy (Octreoscan): a comparative study with CT and MR imaging 总被引:2,自引:0,他引:2
Shi W; Johnston CF; Buchanan KD; Ferguson WR; Laird JD; Crothers JG; McIlrath EM 《QJM : monthly journal of the Association of Physicians》1998,91(4):295-301
A wide variety of neuroendocrine tumours express somatostatin receptors,
and can be visualized by radiolabelled somatostatin analogue scintigraphy.
To investigate the value of [111In]-octreotide scintigraphy (Octreoscan),
48 patients (37 with proven carcinoid, pancreatic endocrine and medullary
carcinoma of thyroid tumours, 11 with neuroendocrine syndromes multiple
endocrine neoplasia (MEN-I) and Zollinger-Ellison syndrome (ZES) were
examined with 111In-DTPA-D-Phe1- octreotide. Scintigrams were obtained at
24 and 48 h, and the results were compared with CT and magnetic resonance
imaging (MRI). Thirty-five of 48 patients had positive [111In]-octreotide
scintigraphy (23/25 (92%) carcinoids, 8/9 (89%) PETs, 4/11 (36%) MEN-I
& ZES). Of the 42 lesions located by conventional imaging techniques,
37 (88%) were also identified by Octreoscan. Unexpected lesions (40 sites),
not detected by CT or MR imaging were found in 24/48 (50%) patients.
[111In]- octreotide scintigraphy has a higher sensitivity for tumour
detection, and is superior to MR imaging and CT scanning in the
identification of previously unsuspected extraliver and lymph node
metastases. It may also be helpful for the localization of clinically
suspected tumours in patients with MEN-I and ZES.
相似文献
70.
目的:制备适合脂肪组织来源的干细胞生长的支架,观察复合支架各组成的体积比率与细胞培养的亲和性.
方法:实验于2006-09/2007-01在大连理工大学干细胞与组织工程研发中心完成.①实验方法:将3.55 g/L Ⅰ型胶原和20 g/L壳聚糖分别以9∶1,7∶3,5∶5,3∶7,1∶9的体积比混合冻干,碳化二亚胺/N-羟基琥珀酰亚胺交联后再次冻干并进行分析.②实验评估:扫描电镜观察不同材料交联前后的微观结构;IPP软件分析计算支架的平均孔径;测量支架的吸水性和孔隙率;通过胶原酶检测支架的体外生物可降解性;扫描电镜和苏木精-伊红染色观察脂肪组织来源的干细胞在复合支架上的生长情况.
结果:①交联前后的微观结构:冻干后的各种支架材料呈白色,表面粗糙,材料内部呈海绵状多孔隙结构,其中以胶原/壳聚糖体积比为9∶1的复合支架最为疏松,1∶9的支架最致密.扫描电镜下支架的胶原含量越高,支架内的胶原丝越多,支架的孔与孔之间相互连通构成了通孔.交联前后支架的形态结构无明显改变.②支架的平均孔径∶交联后体积比为9∶1,7∶3和5∶5的复合支架孔径50~200 μm,可用于细胞的三维培养.③支架的吸水性和孔隙率∶体积比为5∶5的复合支架的吸水性和含水量最高,而7∶3次之;多孔支架在水中未发生明显的溶胀现象;支架的孔隙率均在90%以上.④支架的体外生物可降解性:未交联的支架随着胶原含量的减少,支架的降解速率增加.而交联后随着胶原含量的减少,降解速率减慢,交联后的复合支架降解速度较未交联慢.⑤脂肪组织来源的干细胞在复合支架上的生长情况:脂肪组织来源的干细胞在支架上培养5 d后扫描电镜观察细胞在7∶3的支架上爬行生长并融合成片,苏木精-伊红染色观察支架孔内及表面出现大量的细胞团,并融合成片状,而5∶5支架上黏附生长的细胞较少.
结论:结合支架的孔径、吸水性、孔隙率、体外生物可降解性和细胞与支架的生物相容性,可知体积比为7∶3的复合支架对脂肪组织来源的干细胞的亲和性较好,适于脂肪组织来源的干细胞的三维培养. 相似文献