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61.
N Yang SM Liu LF Zheng T Ji Y Li XL Mi H Xue W Ren JD Xu XH Zhang LS Li Y Zhang JX Zhu 《British journal of pharmacology》2010,159(8):1623-1625
Background and purpose:
5-Hydroxytryptamine (5-HT) is a key regulator of the gastrointestinal system and we have shown that submucosal neuronal 5-HT3 receptors exerted a novel inhibitory effect on colonic ion transport. The aim of the present study was to investigate the precise mechanism(s) underlying this inhibitory effect.Experimental approach:
Mucosa/submucosa or mucosa-only preparations from rat distal colon were mounted in Ussing chambers for measurement of short-circuit current (Isc) as an indicator of ion secretion. Somatostatin release was determined with radioimmunoassay. Intracellular cAMP content was measured with enzyme-linked immunoadsorbent assay (elisa). Immunohistochemical techniques were used to study the expression of 5-HT3 receptors, somatostatin and somatostatin receptors in colonic tissue.Key results:
In rat distal colonic mucosa/submucosa preparations, pretreatment with 5-HT3 receptor antagonists enhanced 5-HT-induced increases in Isc. However, in mucosa-only preparations without retained neural elements, pretreatment with 5-HT3 receptor antagonists inhibited 5-HT-induced ΔIsc. Pretreatment with a somatostatin-2 (sst2) receptor antagonist in mucosa/submucosa preparations augmented 5-HT-induced ΔIsc. Combination of sst2 and 5-HT3 receptor antagonists did not cause further enhancement of 5-HT-induced ΔIsc. Moreover, both sst2 and 5-HT3 receptor antagonists enhanced 5-HT-induced increase in intracellular cAMP concentration in the mucosa/submucosa preparations. 5-HT released somatostatin from rat colonic mucosa/submucosa preparations, an effect prevented by pretreatment with 5-HT3 receptor antagonists. Immunohistochemical staining demonstrated the presence of 5-HT3 receptors on submucosal somatostatin neurons and of sst2 receptors on colonic mucosa.Conclusion and implications:
Activation of neuronal 5-HT3 receptors in the submucosal plexus of rat colon suppressed 5-HT-induced ion secretion by releasing somatostatin from submucosal neurons. 相似文献62.
Jennifer LS Lofgren Michael Esmail Melissa Mobley Amanda McCabe Nancy S Taylor Zeli Shen Susan Erdman Christine Hewes Mark T Whary James G Fox 《Journal of the American Association for Laboratory Animal Science》2012,51(4):436-442
Most academic research colonies of mice are endemically infected with enterohepatic Helicobacter spp. (EHS). We evaluated EHS prevalence in surveillance mice before and after a 10-y period of requiring that imported mice be free of EHS by embryo transfer rederivation or purchase from approved vendors. In 2009, composite fecal samples from CD1 surveillance mice representing colony health in 57 rooms located in 6 facilities were evaluated for EHS infection by using PCR assays. Fecal samples were screened with primers designed to detect all known EHS, and positive samples were further assayed by using primers specific for H. hepaticus, H. bilis, H. rodentium, and H. typhlonicus. Most EHS were detected in surveillance mice within the first month of dirty bedding exposure, with prevalence ranging from 0% to 64% as monoinfections or, more commonly, infections with multiple EHS. Compared with 1999 prevalence data, EHS remained endemic in colonies importing the lowest number of EHS-free mice. EHS were absent or the prevalence was greatly reduced in colonies receiving the highest percentage of EHS-free mice. This study demonstrates that the management decision to require exclusive importation of EHS-free mice reduced EHS prevalence on an institutional scale without intensive labor and expense associated with other techniques or interference with research objectives.Abbreviation: EHS, enterohepatic Helicobacter spp.; ET, embryo transfer; Hb, H. bilis; Hh, H. hepaticus; Hm, H. mastomyrinus; Hr, H. rodentium; Ht, H. typhlonicusEnterohepatic Helicobacter spp. (EHS) infections are endemic in the majority of research mouse colonies. In 2007, 84% of mice shipped from academic institutions worldwide for embryo transfer (ET) rederivation at our institution were PCR-positive for EHS. H. hepaticus (Hh) was detected in 64% of the mouse shipments either as a monoinfection or in combination with other EHS including H. bilis (Hb), H. rodentium (Hr), H. typhlonicus (Ht), and H. mastomyrinus (Hm).30 Although EHS generally cause subclinical infection in immunocompetent mice, opportunistic infections have the potential to confound experimental data in mouse models.9,17,34 Importantly, chronic EHS infection in immunodeficient and select inbred strains of mice can induce liver10 and lower bowel carcinoma,13 typhlocolitis, and rectal prolapse,16,21,28 and reduce reproductive performance.25 In addition, EHS-induced inflammatory responses may alter host immune responses to unrelated experimental infections (for example, promoting elevated systemic IFNγ responses).3,20Key challenges to eradication of EHS from rodent colonies are determining infection status, eliminating endemic infections, and instituting management practices that prevent reinfection. EHS are disseminated through fecal–oral transmission within a colony and are transmissible to surveillance mice through dirty-bedding exposure.1,19,24,32 For routine surveillance, PCR assay of feces or cecal mucosal scrapings for genus-specific Helicobacter 16S rRNA genes is the most efficient means of detecting EHS infection, with speciation (if desired) of positive results by culture, restriction fragment length polymorphism analysis, species-specific PCR, or sequence analysis.34 In 1999, as determined by species-specific PCR assays of cecal scrapings from 59 surveillance mice exposed to dirty bedding from colony mice in 26 rooms representing 4 mouse facilities, EHS were endemic on our campus, with prevalence in surveillance mice of 41% for Hh, 82% for Hr, and 6% for Hb.32 Husbandry practices used to minimize cage-to-cage transmission of EHS included microisolation caging, sanitized forceps to transfer mice, and a cage change order from known Helicobacter-free mice to mice of unknown or known EHS infection status (that is, clean to dirty traffic flow of personnel and equipment).32 Although EHS eradication potentially could be accomplished campus-wide by using labor-intensive antibiotics7,15 and cross-fostering,4,29,31 we hypothesized that a more cost-effective approach, without confounding experimental data, would be to restrict importation of mice to EHS-free sources. Vendors were screened to establish that production colonies were SPF for EHS, and a new requirement was instituted for embryo transfer (ET) rederivation of mice obtained from random sources, typically other academic institutions, replacing traditional quarantine practices. This study used PCR data from 1999 and 2009 to evaluate the success of this approach, which was defined as a marked decrease in the prevalence of EHS infection over time. 相似文献
63.
64.
H Calkins P Yong JM Miller B Olshansky M Carlson JP Saul SK Huang LB Liem LS Klein SA Moser DA Bloch P Gillette E Prystowsky 《Circulation》1999,99(2):262-270
BACKGROUND: The purpose of this study was to evaluate the safety and efficacy of a temperature-controlled radiofrequency catheter ablation system. METHODS AND RESULTS: The patient population included 1050 patients who had undergone ablation of atrioventricular nodal reentrant tachycardia (AVNRT), an accessory pathway (AP), or the atrioventricular junction (AVJ). Ablation was successful in 996 patients. The probability of success was highest among patients who had undergone ablation of the AVJ, lowest in patients who had undergone ablation of an AP, and in between for patients who had undergone ablation of AVNRT. A major complication occurred in 32 patients. Four variables predicted ablation success (AVJ, AVNRT, or left free wall AP ablation and an experienced center). Four factors predicted arrhythmia recurrence (right free wall, posteroseptal, septal, and multiple APs). Two variables predicted development of a complication (structural heart disease and the presence of multiple targets), and 3 variables predicted an increased risk of death (heart disease, lower ejection fraction, and AVJ ablation). CONCLUSIONS: These findings may serve as a guide to clinicians considering therapeutic options in patients who are candidates for ablation. 相似文献
65.
B McKenzie-Green LS Giddings L Buttle K Tahana 《International journal of dental hygiene》2009,7(1):31-38
Abstract: Objectives: Little is known about older persons’ perceptions of oral health and oral health care. The purpose of this study was to explore the viewpoint of older adults’ regarding their oral health care practices. Methods: A qualitative interpretive methodology was employed comprising three analytic levels: coding of data into concepts, analysis of concepts into themes, followed by an in‐depth analysis of relationships within concepts and between themes. In‐depth individual interviews were conducted with 19 participants aged 65 to 87 years. Results: Older people’s decision to access oral health care involves complex and personally meaningful strategies. A dental visit surfaces hopes and fears based on past and present experiences. Mouth and teeth are not merely objects of dental care; they represent a person’s social and relational self. Age‐related changes challenge the relational self as represented in societal ideal images of youth and perfection (the perfect smile). This study highlights older peoples’ resilience and determination when faced with the dilemmas in accessing oral health care – it costs, personally as well as financially. Contrary to the assumption that older peoples’ oral health status is related to neglect, rather for many, it is the result of the intersection of their history with technological advances. Conclusions: These findings challenge oral health care practitioners to be sensitive to the contexts affecting their older client’s oral health care status. They do not ‘just go’ to the dentist; they bring with them their past dental experiences and their hopes for the future. It matters how one is treated at this vulnerable time. 相似文献
66.
M Hill K Finning P Martin J Hogg C Meaney G Norbury G Daniels LS Chitty 《Clinical genetics》2011,80(1):68-75
Hill M, Finning K, Martin P, Hogg J, Meaney C, Norbury G, Daniels G, Chitty LS. Non‐invasive prenatal determination of fetal sex: translating research into clinical practice. The effectiveness and clinical utility of non‐invasive prenatal diagnosis (NIPD) for fetal sex determination using cell‐free fetal DNA (cffDNA) was assessed by undertaking a prospective national audit of UK testing. NIPD was performed using real‐time polymerase chain reaction analysis of the DYS14 or SRY gene in cffDNA extracted from maternal plasma. All cases referred for fetal sex determination from 1 April 2006 to 31 March 2009 were ascertained from two laboratories offering the test. Fetal gender determined by NIPD was compared with that based on ultrasound, invasive test or phenotype at birth. Indication and rate of invasive testing was ascertained. In the first year, results were issued in 150/161 pregnancies tested. Of the 135 with outcome data, results were concordant in 130/135 [96.3% (95% CI 91.6–98.8%)]. Reporting criteria were changed and in the subsequent 511 pregnancies the concordancy rate increased to 401/403 [99.5% (95% CI 98.2–99.9%)]. Over the 3 years only 32.9% (174/528) underwent invasive testing. NIPD for fetal sex determination using cffDNA is highly accurate when performed in National Health Service laboratories if stringent reporting criteria are applied. Parents should be advised of the small risk of discordant results and possible need for repeat testing to resolve inconclusive results. 相似文献
67.
68.
69.
Mandeep Singh MRCSEd Jovina LS See FRCSEd Maria C Aquino MD Lennard SY Thean FRCSEd Paul TK Chew FRCSEd 《Clinical & experimental ophthalmology》2009,37(4):345-351
Background: The aim of this work was to image trabeculectomy blebs using spectral domain optical coherence tomography (SDOCT).
Methods: In this prospective cross-sectional study, patients who had undergone trabeculectomy with at least 3 months of follow up were included. Blebs were imaged using an adapted SDOCT system (Cirrus HD-OCT, Carl Zeiss Meditec Inc., Dublin, CA, USA) and time domain anterior segment optical coherence tomography (ASOCT) (Visante OCT, Carl Zeiss Meditec Inc.). An observer masked to clinical data assessed the utility of SDOCT and ASOCT in visualizing structures in successful and failed blebs.
Results: Fifty-one eyes were imaged, of which 43 (84.3%) were successful. SDOCT showed wall thickening (93.0% vs. 67.4%, P = 0.006) and discrete hyporeflective spaces in the wall (88.4% vs. 14.0%, P < 0.0001) in a greater proportion of successful blebs than ASOCT. SDOCT showed the bleb cavity (23.3% vs. 48.8%, P = 0.02), scleral flap (34.9% vs. 90.7%, P < 0.0001), subflap space (20.9% vs . 72.1%, P < 0.0001) and ostium (9.3% vs. 88.4%, P < 0.0001) in fewer successful blebs than ASOCT. The internal ostium was not visualized in any failed bleb using SDOCT, whereas ASOCT showed the ostium in 87.5% of failed blebs ( P = 0.001). SDOCT showed cystic spaces in the bleb wall in a greater proportion of successful blebs than failed blebs (88.4% vs. 37.5%, P = 0.005).
Conclusions: SDOCT imaging was able to show fine superficial features in the bleb wall. However, SDOCT had limited clinical utility in that it did not provide useful information about deep features such as flap position, bleb cavity formation or patency of the subflap space and internal ostium. 相似文献
Methods: In this prospective cross-sectional study, patients who had undergone trabeculectomy with at least 3 months of follow up were included. Blebs were imaged using an adapted SDOCT system (Cirrus HD-OCT, Carl Zeiss Meditec Inc., Dublin, CA, USA) and time domain anterior segment optical coherence tomography (ASOCT) (Visante OCT, Carl Zeiss Meditec Inc.). An observer masked to clinical data assessed the utility of SDOCT and ASOCT in visualizing structures in successful and failed blebs.
Results: Fifty-one eyes were imaged, of which 43 (84.3%) were successful. SDOCT showed wall thickening (93.0% vs. 67.4%, P = 0.006) and discrete hyporeflective spaces in the wall (88.4% vs. 14.0%, P < 0.0001) in a greater proportion of successful blebs than ASOCT. SDOCT showed the bleb cavity (23.3% vs. 48.8%, P = 0.02), scleral flap (34.9% vs. 90.7%, P < 0.0001), subflap space (20.9% vs . 72.1%, P < 0.0001) and ostium (9.3% vs. 88.4%, P < 0.0001) in fewer successful blebs than ASOCT. The internal ostium was not visualized in any failed bleb using SDOCT, whereas ASOCT showed the ostium in 87.5% of failed blebs ( P = 0.001). SDOCT showed cystic spaces in the bleb wall in a greater proportion of successful blebs than failed blebs (88.4% vs. 37.5%, P = 0.005).
Conclusions: SDOCT imaging was able to show fine superficial features in the bleb wall. However, SDOCT had limited clinical utility in that it did not provide useful information about deep features such as flap position, bleb cavity formation or patency of the subflap space and internal ostium. 相似文献
70.
贺国丽 《国外医学:妇产科学分册》2009,(2):147-147
根据沙利度胺和拓扑特肯的活性机制和具抗血管生成的特性,本研究比较了沙利度胺联合拓扑特肯与拓扑特肯单用在复发的上皮性卵巢、输卵管、腹膜癌的疗效。
此项历时4年的多中心的前瞻性随机2期研究得到明尼苏达大学妇女癌症中心的协助。人选者具有下列条件之一:①在以铂类和紫杉醇为基础的初始化疗后未控。 相似文献