首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   24篇
  免费   3篇
基础医学   3篇
临床医学   1篇
内科学   15篇
神经病学   5篇
外科学   1篇
预防医学   1篇
肿瘤学   1篇
  2018年   1篇
  2015年   2篇
  2013年   4篇
  2011年   1篇
  2008年   5篇
  2007年   2篇
  2006年   1篇
  2005年   1篇
  2004年   1篇
  2003年   1篇
  2001年   4篇
  2000年   1篇
  1999年   1篇
  1997年   1篇
  1991年   1篇
排序方式: 共有27条查询结果,搜索用时 15 毫秒
1.
OBJECTIVES: Intestinal inflammation is associated with enteric nervous system alterations, at both inflamed and noninflamed sites. The perception of stimuli from the GI tract is enhanced during inflammatory conditions, but it is unknown whether visceral hypersensitivity is limited to the inflamed area or diffuse throughout the entire GI tract. Moreover, although stress can reactivate inflammatory processes in the gut, it is unknown if this can alter perception from the GI tract. Our aim was to determine if patients with ulcerative colitis (UC) have increased esophageal sensitivity to distention and whether this is modified by experimental stress. METHODS: Ten UC patients and 12 healthy volunteers (HVs) underwent gradual balloon distension of the esophagus to assess their visceral sensitivity. Perceptive and pain thresholds were evaluated in basal conditions and after induction of experimental stress (cold water pressure test) while blood pressure and heart rate were monitored. RESULTS: Patients with UC had perceptive thresholds to distension similar to HVs (14.8+/-2.0 ml of air vs 14.5+/-3.0 ml); in contrast, the volume increment needed to evoke pain was significantly lower in UC patients than in HVs (58.9% vs 149.9%, p < 0.05). Physical stress caused a similar decrease in perceptive thresholds in HVs (-29.1+/-8.4%) and patients (-17.7+/-9.1%), but pain thresholds were significantly decreased only in HVs (-28.3+/-7.1% vs -11.5+/-12.3%). CONCLUSIONS: UC is characterized by increased esophageal sensitivity, indicating the existence of diffuse hyperalgesia during intestinal inflammatory processes. This increased sensitivity may account for the frequent upper GI symptoms these patients complain of when in clinical remission.  相似文献   
2.
OBJECTIVES: Small intestinal permeability is often increased in patients with Crohn's disease and may be pathogenic for clinical relapses. No effective prophylactic treatment is available for these patients. The aim of this study was to ascertain whether zinc supplementation may improve intestinal permeability. METHODS: We studied 12 patients with quiescent Crohn's disease who had been in remission for at least 3 months and had increased intestinal permeability on two separate occasions within the last 2 months. Patients received oral zinc sulfate supplements (110 mg three times a day) for 8 weeks and were followed-up for 12 months thereafter to monitor relapses. RESULTS: We found that the lactulose/mannitol ratio was significantly higher before supplementation than after (0.041 +/- 0.003 versus 0.026 +/- 0.005). During follow-up, 10 patients had normal intestinal permeability and did not relapse; of the remaining two who had increased intestinal permeability, one relapsed. CONCLUSIONS: Our findings show that zinc supplementation can resolve permeability alterations in patients with Crohn's disease in remission. Improving intestinal barrier function may contribute to reduce the risk of relapse in Crohn's disease.  相似文献   
3.
The long-term ecological response to recurrent deforestation associated with shifting cultivation remains poorly investigated, especially in the dry tropics. We present a study of phosphorus (P) dynamics in the southern Yucatán, highlighting the possibility of abrupt shifts in biogeochemical cycling resulting from positive feedbacks between vegetation and its limiting resources. After three cultivation–fallow cycles, available soil P declines by 44%, and one-time P inputs from biomass burning decline by 76% from mature forest levels. Interception of dust-borne P (“canopy trapping”) declines with lower plant biomass and leaf area, limiting deposition in secondary forest. Potential leaching losses are greater in secondary than in mature forest, but the difference is very small compared with the difference in P inputs. The decline in new P from atmospheric deposition creates a long-term negative ecosystem balance for phosphorus. The reduction in soil P availability will feed back to further limit biomass recovery and may induce a shift to sparser vegetation. Degradation induced by hydrological and biogeochemical feedbacks on P cycling under shifting cultivation will affect farmers in the near future. Without financial support to encourage the use of fertilizer, farmers could increase the fallow period, clear new land, or abandon agriculture for off-farm employment. Their response will determine the regional balance between forest loss and forest regrowth, as well as the frequency of use and rate of recovery at a local scale, further feeding back on ecological processes at multiple scales.  相似文献   
4.
5.
Objective. The treatment of celiac disease is based on lifelong withdrawal of foods containing gluten. Unfortunately, compliance with a gluten-free diet has proved poor in many patients (mainly due to its low palatability), emphasizing the need for cereal varieties that are not toxic for celiac patients. In evolutionary terms, Triticum monococcum is the oldest and most primitive cultivated wheat. The aim of this study was to evaluate the toxicity of T. monococcum on small intestinal mucosa, using an in vitro organ culture system.

Material and methods. Distal duodenum biopsies of 12 treated celiac patients and 17 control subjects were cultured for 24?h with T. aestivum (bread) gliadin (1?mg/ml) or with T. monococcum gliadin (1?mg/ml). Biopsies cultured with medium alone served as controls. Each biopsy was used for conventional histological examination and for immunohistochemical detection of CD3?+?intraepithelial lymphocytes (IELs) and HLA-DR. Secreted cytokine protein interferon-γ (IFN–γ) was measured in the culture supernatant using an enzyme-linked immunoadsorbent assay.

Results. Significant morphological changes, HLA-DR overexpression in the crypt epithelium and an increased number of CD3?+?IELs, found after bread gliadin exposure, were not observed in celiac biopsies cultured with T. monococcum gliadin. In contrast, with bread gliadin, there was no significant IFN-γ response after culture with monococcum gliadin. Similarly, biopsies from normal controls did not respond to bread or monococcum gliadin stimulation.

Conclusions. These data show a lack of toxicity of T. monococcum gliadin in an in vitro organ culture system, suggesting new dietary opportunities for celiac patients.  相似文献   
6.
OBJECTIVE: The treatment of celiac disease is based on lifelong withdrawal of foods containing gluten. Unfortunately, compliance with a gluten-free diet has proved poor in many patients (mainly due to its low palatability), emphasizing the need for cereal varieties that are not toxic for celiac patients. In evolutionary terms, Triticum monococcum is the oldest and most primitive cultivated wheat. The aim of this study was to evaluate the toxicity of T. monococcum on small intestinal mucosa, using an in vitro organ culture system. MATERIAL AND METHODS: Distal duodenum biopsies of 12 treated celiac patients and 17 control subjects were cultured for 24 h with T. aestivum (bread) gliadin (1 mg/ml) or with T. monococcum gliadin (1 mg/ml). Biopsies cultured with medium alone served as controls. Each biopsy was used for conventional histological examination and for immunohistochemical detection of CD3 + intraepithelial lymphocytes (IELs) and HLA-DR. Secreted cytokine protein interferon-gamma (IFN-gamma) was measured in the culture supernatant using an enzyme-linked immunoadsorbent assay. RESULTS: Significant morphological changes, HLA-DR overexpression in the crypt epithelium and an increased number of CD3 + IELs, found after bread gliadin exposure, were not observed in celiac biopsies cultured with T. monococcum gliadin. In contrast, with bread gliadin, there was no significant IFN-gamma response after culture with monococcum gliadin. Similarly, biopsies from normal controls did not respond to bread or monococcum gliadin stimulation. CONCLUSIONS: These data show a lack of toxicity of T. monococcum gliadin in an in vitro organ culture system, suggesting new dietary opportunities for celiac patients.  相似文献   
7.
8.
This study analysed the early linguistic development of Italian pre-term children. Samples of spontaneous pre-linguistic and verbal production were recorded at 12 and 18 months of age from two groups of children: 24 pre-term children and 15 full-term children. The Italian version of the MacArthur-Bates Questionnaire was administered at 24 months of age. Comparisons between these two groups reveal differences in many aspects of phonetic and phonological development, such as consonantal inventory at 12 and 18 months of age and syllabic babbling complexity at 18 months of age. Results evidenced that birth weight was related with phonological skills exhibited at 18 months of age, and these skills in turn are related with vocabulary size at 24 months of age. Data are discussed within a theoretical framework that hypothesizes that early phonetic abilities have long-lasting effects on the process of language acquisition.  相似文献   
9.
Several bacterial and host-related factors concur in causing Helicobacter pylori eradication failure. We ascertained the role of bacterial virulence genes (cagA, vacA), clarithromycin resistance [Cla(R), 23S ribosomal RNA (rRNA) mutations], host polymorphism of CYP2C19 (polyphosphoinositide, PPI, metabolism) and of the cytokines IL-1B-31C>T, IL-1RN VNTR, IFN-gamma+874A>T, TNF-alpha-1031T>C, TNF-alpha-857C>T, TNF-alpha-376G>A, TNF-alpha-308G>A, TNF-alpha-238G>A, IL-10-1082A>G, IL-10-819C>T, IL-10-592C>A, IL-12A+6686G>A, IL-12B+15485A>C. Two groups of H. pylori-infected and H. pylori-treated patients were retrospectively identified: 45 not eradicated and 57 eradicated. Treatment failure was significantly correlated with Cla(R) (all resistant strains in non-eradicated patients); with TNF-alpha-238, IL10-819, IL10-592, IL-12B+15485 single nucleotide polymorphism (SNP); with IL10 ATA/ATA haplotype; and with antral inflammatory grade. On considering Cla(S)-infected patients only, logistic regression analysis (eradication = dependent; TNF-alpha-238, IL12B + 15485 genotypes, IL10 ATA/ATA as present or absent, antral gastritis grade = covariates) confirmed as significantly correlated with eradication antral gastritis grade only (Exp(B) = 6.48; 95% CI, 1.2-35.01). In conclusion, the bacterial determinant causing triple therapy failure is clarithromycin resistant, being virulence genes not involved. The host related factors that favor eradication are those linked to inflammation: a higher inflammatory infiltrate in the mucosa, possibly favored by genotypes able to down regulate the anti-inflammatory cytokine response, enhance the chance of eradication success.  相似文献   
10.
Abstract

Objective. The aim of this explorative study was to evaluate double-balloon enteroscopy (DBE) as a new tool for collecting mucosal biopsies from well-defined parts of the entire small and large bowel in patients with type 2 diabetes and in matched healthy subjects. Material and methods. Twelve subjects with type 2 diabetes and 12 body mass index and age-matched healthy subjects underwent anterograde and retrograde DBE under nurse-administered propofol sedation on two separate days. We attempted to collect two mucosal biopsies from every 30 cm from pylorus to rectum. Results. A mean of 21 biopsy sites were sampled in the diabetic group versus 25 in the healthy group. In 4 out of 24 patients (2 [17%] from each group) sampling from the entire gastrointestinal system was possible. Mean depth of maximal insertion (anterograde) was 478 ± 32 cm in patients with type 2 diabetes versus 465 ± 44 cm in healthy subjects (p = 0.81) and with retrograde access 230 ± 36 cm (type 2 diabetes) versus 207 ± 26 cm (healthy subjects). Conclusions. DBE is a minimally invasive way of collecting fresh biopsies from the entire gastrointestinal tract and, thus provides research and clinical communities with a new possibility to access hitherto unexplored human anatomy and physiology.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号