Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 52
Filtrar
1.
Sci Rep ; 6: 23537, 2016 Mar 24.
Artículo en Inglés | MEDLINE | ID: mdl-27009234

RESUMEN

The existence of a strong internal magnetic field allows probing of the interior through both long term changes of and short period fluctuations in that magnetic field. Venus, while Earth's twin in many ways, lacks such a strong intrinsic magnetic field, but perhaps short period fluctuations can still be used to probe the electrical conductivity of the interior. Toward the end of the Venus Express mission, an aerobraking campaign took the spacecraft below the ionosphere into the very weakly electrically conducting atmosphere. As the spacecraft descended from 150 to 140 km altitude, the magnetic field became weaker on average and less noisy. Below 140 km, the median field strength became steady but the short period fluctuations continued to weaken. The weakness of the fluctuations indicates they might not be useful for electromagnetic sounding of the atmosphere from a high altitude platform such as a plane or balloon, but possibly could be attempted on a lander.

2.
Br J Cancer ; 106(7): 1320-30, 2012 Mar 27.
Artículo en Inglés | MEDLINE | ID: mdl-22453125

RESUMEN

BACKGROUND: Side population (SP) cells and their relationship to stem cell-like properties have been insufficiently studied in colorectal cancer (CRC). MicroRNAs (miRNAs) have attracted much attention but their roles in the maintenance of SP phenotype remain unclear. METHODS: The SPs from CRC cell lines and primary cell cultures were analysed for stem cell-like properties. MiRNA microarray analysis identified miR-328 as a potential stemness miRNA of SP phenotype. The level of miR-328 expression in clinical samples and its correlation with SP fraction were determined. Gain-of-function and loss-of-function studies were performed to examine its roles in cancer stem-like SP cells. Furthermore, bioinformatics prediction and experimental validation were used to identify miR-328 target genes. RESULTS: The SP cells sorted from CRC possess cancer stem cell (CSC)-like properties, including self-renewal, differentiation, resistance to chemotherapy, invasive and strong tumour formation ability. MiR-328 expression was significantly reduced in SP cells compared with Non-SP cells (P<0.05). Moreover, miR-328 expression was downregulated in CRC (n=33, P<0.05) and low miR-328 expression tend to correlate with high SP fraction (n=15, r=0.6559, P<0.05, Pearson's correlation). Functional studies indicated that miR-328 expression affects the number of SP cells. In addition, miR-328 overexpression reversed drug resistance and inhibited cell invasion of SP cells. Furthermore, luciferase reporter assay demonstrated that miR-328 directly targets ABCG2 and MMP16 and affects the levels of mRNA and protein expression in SP cells. CONCLUSION: These findings indicate that CRC contain cancer stem-like SP cells. MiR-328 has an important role in maintaining cancer stem-like SP phenotype that may be a potential target for effective CRC therapy.


Asunto(s)
Neoplasias Colorrectales/genética , MicroARNs/fisiología , Células Madre Neoplásicas/fisiología , Transportador de Casetes de Unión a ATP, Subfamilia G, Miembro 2 , Transportadoras de Casetes de Unión a ATP/genética , Diferenciación Celular , Línea Celular Tumoral , Transformación Celular Neoplásica , Neoplasias Colorrectales/patología , Regulación hacia Abajo , Resistencia a Antineoplásicos , Citometría de Flujo , Regulación Neoplásica de la Expresión Génica , Humanos , Metaloproteinasa 16 de la Matriz/genética , MicroARNs/metabolismo , Invasividad Neoplásica , Proteínas de Neoplasias/genética
4.
Neurogastroenterol Motil ; 23(1): 62-9, e6, 2011 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-20723070

RESUMEN

BACKGROUND: Compelling evidence shows that vagal afferents mediate antinociception in response to visceral insults. Our recent findings implied that luminal serotonin (5-hydroxytryptamine, 5-HT) might mediate chronic food allergen sensitized visceral hyperalgesia, in which vagal afferents might be implicated. Here, to test this hypothesis, we investigated the effects of luminal infused 5-HT on visceral nociception and the involvement of vagal antinociceptive pathway. METHODS: The vagus-intact or vagotomized rats were given acute intraluminally or intraperitoneally administered 5-HT, or chronic luminal infusion of 5-HT. The visceromotor response (VMR) to colorectal distension (CRD) was electrophysiologically recorded. KEY RESULTS: Acute intraluminal infusion of 5-HT (10 or 100 nmol) significantly attenuated VMR to CRD, while systemic administered 5-HT at similar doses resulted in markedly augmented nociception. Pretreatment with luminal application of granisetron or lidocaine, or pharmacological depletion of endogenous 5-HT with injection of p-chlorophenylalanine, a 5-HT synthesis inhibitor, and subdiaphragmatic vagotomy or functional deafferentation with capsaicin abolished the effect of luminal (but not systemic) 5-HT. Chronic infusion of 5-HT (10 nmol d(-1) for 5 days) produced gradual augmentation of baseline VMR. And, the VMR to CRD after 5-HT infusion decreased on day 1 and 2, then gradually increased from day 3. Surgical vagotomy or daily preperfusion with granisetron canceled these time-dependent patterns. CONCLUSIONS & INFERENCES: Luminal 5-HT time-dependently modulates vagal afferent driven antinociception. Acute infusion of 5-HT attenuates visceral nociception via activation of vagal afferent 5-HT type 3 receptors (5-HT(3)Rs)within intestinal mucosa; while chronic luminal 5-HT caused gradually developed visceral hyperalgesia, which may also involve vagal 5-HT(3)Rs.


Asunto(s)
Vías Aferentes/efectos de los fármacos , Analgésicos/farmacología , Colon/fisiopatología , Serotonina/administración & dosificación , Serotonina/farmacología , Nervio Vago/efectos de los fármacos , Animales , Capsaicina/farmacología , Colon/inervación , Dilatación Patológica , Hipersensibilidad a los Alimentos/fisiopatología , Granisetrón/farmacología , Hiperalgesia/tratamiento farmacológico , Mucosa Intestinal/efectos de los fármacos , Mucosa Intestinal/inervación , Lidocaína/farmacología , Masculino , Dolor/tratamiento farmacológico , Dolor/fisiopatología , Ratas , Ratas Sprague-Dawley , Serotonina/uso terapéutico , Antagonistas de la Serotonina/farmacología , Factores de Tiempo , Vagotomía
5.
J Clin Pharm Ther ; 34(1): 41-53, 2009 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-19125902

RESUMEN

BACKGROUND: As standard triple therapies of achieve unsatisfactory eradication of Helicobacter pylori, several alternative regimens have been proposed. OBJECTIVES: To systematically evaluate whether sequential treatment eradicates H. pylori infection better than standard triple therapies and compare the risk of adverse events with these two regimens. METHODS: We searched electronic databases up to February 2008 for studies evaluating the efficacy of the 10-day sequential therapy vs. standard triple regimens for eradication of H. pylori. The pooled risk ratios (RR) and 95% confidence intervals (95% CI) were calculated. RESULTS: We identified 11 randomized trials, including eight full-text manuscripts and three abstracts. Pooled analysis demonstrated clear superiority of the sequential therapy over 7-day triple regimen with an RR of 1.23 (95% CI 1.19-1.27), and over 10-day triple regimen with a RR of 1.16 (95% CI 1.10-1.23). Adverse event rates were similar. For sequential therapy vs. 7-day triple therapies, RR = 0.96, 95% CI 0.70-1.31. CONCLUSIONS: Sequential therapy was associated with a higher eradication rate of H. pylori compared with both 7-day triple regimen and 10-day triple regimen.


Asunto(s)
Antibacterianos/uso terapéutico , Antiulcerosos/uso terapéutico , Infecciones por Helicobacter/tratamiento farmacológico , Helicobacter pylori , Inhibidores de la Bomba de Protones/uso terapéutico , Amoxicilina/uso terapéutico , Bismuto/uso terapéutico , Claritromicina/uso terapéutico , Esquema de Medicación , Quimioterapia Combinada , Humanos , Omeprazol/uso terapéutico , Ranitidina/análogos & derivados , Ranitidina/uso terapéutico , Tinidazol/uso terapéutico , Resultado del Tratamiento
6.
Aliment Pharmacol Ther ; 26(5): 653-63, 2007 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-17697199

RESUMEN

BACKGROUND: The use of heparin for the treatment of ulcerative colitis has been evaluated in several open and controlled trials, with varying outcomes. AIM: To evaluate the efficacy and safety of heparin as supplemental therapy compared with conventional therapy in patients with ulcerative colitis. METHODS: All randomized trials comparing heparin supplementation to conventional therapy were included from electronic databases. Statistical analysis was performed with review manager 4.2.8 (The Cochrane Collaboration, Oxford, UK). Sub-analysis and sensitivity analysis were also performed. RESULTS: Eight randomized-controlled trials, investigating a total of 454 participants, met the inclusion criteria. The odds ratio (OR) for the efficacy of heparin supplementation vs. conventional therapy was 0.78 (95% CI = 0.50-1.21). Few serious adverse events were observed. The OR for the efficacy of unfractionated heparin and low-molecular-weight heparin vs. conventional therapy was 0.26 (95% CI = 0.07-0.93) and 0.92 (95% CI = 0.57-1.47), respectively. The OR for the efficacy of heparin vs. conventional therapy with placebo was 0.87 (95% CI = 0.53-1.44). CONCLUSIONS: Our meta-analysis suggests that administration of heparin in patients with ulcerative colitis is safe, but no additive benefit over conventional therapy is indicated.


Asunto(s)
Anticoagulantes/efectos adversos , Colitis Ulcerosa/tratamiento farmacológico , Heparina/efectos adversos , Análisis de Varianza , Anticoagulantes/administración & dosificación , Quimioterapia Combinada , Femenino , Heparina/administración & dosificación , Humanos , Masculino , Oportunidad Relativa , Ensayos Clínicos Controlados Aleatorios como Asunto , Sensibilidad y Especificidad , Resultado del Tratamiento
7.
Aliment Pharmacol Ther ; 25(2): 155-68, 2007 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-17229240

RESUMEN

BACKGROUND: Recent evidence found probiotics could inhibit Helicobacter pylori colonization from both in vitro and in vivo studies. AIM: To systematically evaluate whether adding probiotics to anti-H. pylori regimens could improve eradication rates and reduce side effects during anti-H. pylori treatment. METHODS: Eligible articles were identified by searches of electronic databases. We included all randomized trials comparing probiotics supplementation to placebo or no treatment during anti-H. pylori regimens. Statistical analysis was performed with Review Manager 4.2.8. Subanalysis/Sensitivity analysis was also performed. RESULTS: We identified 14 randomized trials (n = 1671). Pooled H. pylori eradication rates were 83.6% (95% CI = 80.5-86.7%) and 74.8% (95% CI = 71.1-78.5%) for patients with or without probiotics by intention-to-treat analysis, respectively, the odds ratio (OR) was 1.84 (95% CI = 1.34-2.54); the occurrence of total side effects were 24.7% (95% CI = 20.0-29.4%) and 38.5% (95% CI = 33.0-44.1%) for groups with or without probiotics, especially for diarrhoea, the summary OR was 0.44 (95% CI = 0.30-0.66). CONCLUSIONS: Our review suggests that supplementation with probiotics could be effective in increasing eradication rates of anti-H. pylori therapy, and could be considered helpful for patients with eradication failure. Furthermore, probiotics show a positive impact on H. pylori therapy-related side effects.


Asunto(s)
Antibacterianos/uso terapéutico , Infecciones por Helicobacter/dietoterapia , Helicobacter pylori , Probióticos/uso terapéutico , Combinación de Medicamentos , Infecciones por Helicobacter/tratamiento farmacológico , Humanos , Ensayos Clínicos Controlados Aleatorios como Asunto
8.
Endoscopy ; 38(8): 836-40, 2006 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-17001575

RESUMEN

BACKGROUND AND STUDY AIMS: Capsule endoscopy is a new diagnostic method allowing painless visualization of the entire small bowel. However, there is as yet no standardized protocol for bowel preparation before the examination. The aim of this study was to assess the effectiveness of simeticone in reducing bowel gas bubbles in patients undergoing capsule endoscopy. PATIENTS AND METHODS: A randomized, prospective, and controlled study was conducted, including 56 patients, from March to October 2004. The patients were randomly allocated to groups receiving either simeticone or no simeticone, on the basis of a computer-generated random number table. Patients in the simeticone group (n = 28) received 300 mg simeticone for bowel preparation 20 min before capsule endoscopy, while patients in the non-simeticone group (n = 28) received no medication for bowel preparation. Two experienced endoscopists assessed and graded the visibility of the mucosa and intraluminal gas bubbles in a single-blinded fashion. RESULTS: The visibility of the mucosa in the proximal small bowel in patients who received preparation with simeticone was considered to be better, with fewer intraluminal bubbles, than in those without bowel preparation ( P < 0.025). Interobserver agreement was excellent ( R > or = 0.8, P < 0.05). No adverse effects of simeticone were observed. CONCLUSIONS: Simeticone administration before capsule endoscopy improves the visualization of the mucosa in the proximal small intestine.


Asunto(s)
Antiespumantes , Endoscopios en Cápsulas , Endoscopía Gastrointestinal/métodos , Simeticona , Adolescente , Adulto , Anciano , Niño , Preescolar , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos
9.
J Clin Pathol ; 58(9): 927-31, 2005 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-16126872

RESUMEN

BACKGROUND: Gastrin G cells and somatostatin D cells are important regulators of gastric acid secretion and alterations in their relative numbers may play a key role in gastroduodenal disease. AIM: To investigate the effect of Helicobacter pylori infection on the density of immunoreactive G and D cells in gastric antral and corpus biopsies from patients with dyspeptic complaints. METHODS: One hundred and twenty two patients with dyspeptic complaints had two antrum and two corpus biopsies taken during upper endoscopy. The severity of inflammation and the density of H pylori were evaluated semiquantitatively. In addition, the density and distribution of neuroendocrine cells, especially G and D cells, were examined using immunohistochemistry. Patients were divided into three groups, those with H pylori positive gastritis, H pylori negative gastritis, and histologically normal gastric mucosa. RESULTS: The number of immunoreactive G cells was significantly higher and the number of immunoreactive D cells lower in patients with H pylori positive gastritis compared with H pylori negative gastritis or histological normal gastric mucosa. The percentage of G cells as a percentage of mucosal endocrine cells was also raised and that of D cells was decreased. CONCLUSIONS: Helicobacter pylori infection produces alterations in the number of endocrine cells responsible for regulating acid secretion in relation to intragastric pH and feeding. The alterations correlate best with the severity of inflammation and not with H pylori density.


Asunto(s)
Células Secretoras de Gastrina/patología , Gastritis/microbiología , Infecciones por Helicobacter , Helicobacter pylori/aislamiento & purificación , Células Secretoras de Somatostatina/patología , Adolescente , Adulto , Anciano , Cromograninas/metabolismo , Dispepsia/metabolismo , Dispepsia/microbiología , Dispepsia/patología , Femenino , Gastrinas/metabolismo , Gastritis/metabolismo , Gastritis/patología , Infecciones por Helicobacter/metabolismo , Infecciones por Helicobacter/patología , Humanos , Técnicas para Inmunoenzimas , Masculino , Persona de Mediana Edad , Antro Pilórico/patología , Índice de Severidad de la Enfermedad , Somatostatina/metabolismo
10.
Aliment Pharmacol Ther ; 21(1): 73-81, 2005 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-15644048

RESUMEN

BACKGROUND: Recent studies suggest that the Helicobacter pylori eradication rate in patients with non-ulcer dyspepsia is lower when compared to patients with peptic ulcer diseases. AIM: The aim of this study was to study the efficacy of triple therapy for H. pylori infection in patients with duodenal ulcer vs. patients with non-ulcer dyspepsia. METHODS: A total of 582 Chinese patients with proven H. pylori infection were recruited to receive: omeprazole 20 mg, amoxicillin 1000 mg and clarithromycin 500 mg all given twice daily for 7 days (OCA regime). Endoscopy with rapid urease test, histology and culture were performed before treatment. Post-treatment H. pylori status was determined by (13)C-urea breath test. Metronidazole, clarithromycin and amoxicillin resistance was defined as minimum inhibitory concentration (MIC) of >8 microg/mL, >1 microg/mL and >1 microg/mL, respectively. RESULTS: A significantly higher (intention-to-treat/per-protocol) eradication rate was found in patients with duodenal ulcer than those with non-ulcer dyspepsia (91/94% vs. 84/88% respectively, P = 0.011 and P = 0.016). Clarithromycin resistance rate was higher in patients with non-ulcer dyspepsia than those with duodenal ulcer (14% vs. 6%, P = 0.015). Clarithromycin resistance (40% vs. 5%, P < 0.001, OR 12, 95% CI: 5.7-24.3) and the diagnosis of non-ulcer dyspepsia (91% vs. 84%, P = 0.011, OR 2.0, 95% CI: 1.2-3.3) significantly affected the success of H. pylori eradication. CONCLUSION: Clarithromycin resistance accounts for the significantly lower and suboptimal H. pylori eradication rate of OCA regimen in Chinese patients with non-ulcer dyspepsia compared to those with duodenal ulcer.


Asunto(s)
Quimioterapia Combinada/uso terapéutico , Úlcera Duodenal/microbiología , Dispepsia/microbiología , Infecciones por Helicobacter/tratamiento farmacológico , Helicobacter pylori , Adolescente , Adulto , Anciano , Amoxicilina/uso terapéutico , Antiulcerosos/uso terapéutico , Pueblo Asiatico/etnología , Claritromicina/uso terapéutico , Resistencia a Medicamentos , Úlcera Duodenal/etnología , Dispepsia/etnología , Femenino , Infecciones por Helicobacter/etnología , Humanos , Masculino , Metronidazol/uso terapéutico , Persona de Mediana Edad , Omeprazol/uso terapéutico , Cooperación del Paciente , Resultado del Tratamiento
11.
Aliment Pharmacol Ther ; 16(4): 793-8, 2002 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-11929398

RESUMEN

AIM: To test the efficacy of omeprazole, furazolidone and amoxicillin triple therapy for the treatment of Helicobacter pylori infection after failure of standard first-line therapy recommended by the Asia-Pacific Consensus on the management of H. pylori infection. METHODS: Patients with failed H. pylori eradication received omeprazole, 20 mg, furazolidone, 100 mg, and amoxicillin, 1 g, all twice daily for 1 week. Endoscopy (CLO test, histology and culture) was performed before treatment. Post-treatment H. pylori status was determined by 13C-urea breath test 6 weeks later. RESULTS: Fifty patients were recruited. Resistance to metronidazole, clarithromycin and both drugs was in the range of 50-64%, 60-75% and 40-50%, respectively, after failure of first-line therapy. Amoxicillin resistance was not found. The intention-to-treat and per protocol H. pylori eradication rates were 52% and 53%, respectively. Patients with double resistance to metronidazole and clarithromycin showed the lowest eradication rate (38%), which was significantly lower than that of patients with sensitive strains (88%). Side-effects were minimal and compliance was excellent (98%). CONCLUSIONS: One-week omeprazole, furazolidone and amoxicillin rescue therapy achieved a high eradication rate in strains sensitive to metronidazole and clarithromycin. This is a cheap and safe rescue regimen when guided by pre-treatment sensitivity testing.


Asunto(s)
Amoxicilina/uso terapéutico , Antiinfecciosos Locales/uso terapéutico , Antiulcerosos/uso terapéutico , Furazolidona/uso terapéutico , Infecciones por Helicobacter/tratamiento farmacológico , Helicobacter pylori/efectos de los fármacos , Omeprazol/uso terapéutico , Adulto , Anciano , Amoxicilina/administración & dosificación , Antiinfecciosos Locales/administración & dosificación , Antiulcerosos/administración & dosificación , Farmacorresistencia Bacteriana Múltiple , Quimioterapia Combinada , Femenino , Furazolidona/administración & dosificación , Infecciones por Helicobacter/diagnóstico , Infecciones por Helicobacter/microbiología , Humanos , Masculino , Pruebas de Sensibilidad Microbiana , Persona de Mediana Edad , Omeprazol/administración & dosificación , Proyectos Piloto , Insuficiencia del Tratamiento
12.
J Clin Pathol ; 55(2): 133-7, 2002 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-11865009

RESUMEN

AIM: To investigate the relation between Helicobacter pylori associated gastroduodenal diseases and lymphoid tissue hyperplasia in the antral mucosa and to pursue its evolution after eradication of H pylori. METHODS: Gastric antral biopsy specimens were obtained from 438 patients with H pylori positive gastroduodenal diseases (185 chronic gastritis, 69 gastric ulcer, and 184 duodenal ulcer) and 50 H pylori negative healthy controls. Lymphoid follicles and aggregates were counted and other pathological features were scored according to the updated Sydney system for classification of chronic gastritis. After a course of anti-H pylori treatment, biopsy specimens were obtained at four to six weeks, 12 months, and 24 months in the chronic gastritis patient group. RESULTS: The total prevalence of lymphoid follicles and aggregates in the biopsies was 79.9% (350 of 438; 95% confidence intervals (CI), 0.76 to 0.84). The prevalence and density of lymphoid follicles and aggregates were significantly different in the various gastroduodenal diseases. The highest prevalence (89.9%; 95% CI, 0.83 to 0.97) and density (0.82) of lymphoid follicles and aggregates occurred in patients with gastric ulcers. The lowest prevalence of lymphoid follicles and aggregates was found in patients with chronic gastritis (74.6%; 95% CI, 0.68 to 0.81), and the lowest density of lymphoid follicles and aggregates (0.56) was seen in patients with duodenal ulcers. The prevalence and density of lymphoid follicles and aggregates correlated strongly with the activity and severity of gastric antral mucosal inflammation. The eradication of H pylori resulted in a decrease in the prevalence and density of lymphoid follicles and aggregates. CONCLUSION: The prevalence and density of lymphoid follicles and aggregates in gastric antral mucosal biopsies correlated closely with H pylori infection.


Asunto(s)
Infecciones por Helicobacter/complicaciones , Helicobacter pylori , Seudolinfoma/microbiología , Gastropatías/microbiología , Adolescente , Adulto , Anciano , Enfermedad Crónica , Úlcera Duodenal/microbiología , Úlcera Duodenal/patología , Femenino , Estudios de Seguimiento , Mucosa Gástrica/patología , Gastritis/microbiología , Gastritis/patología , Infecciones por Helicobacter/tratamiento farmacológico , Humanos , Masculino , Persona de Mediana Edad , Seudolinfoma/patología , Gastropatías/patología , Úlcera Gástrica/microbiología , Úlcera Gástrica/patología
13.
Gut ; 50(1): 61-4, 2002 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-11772968

RESUMEN

BACKGROUND: A decrease in folic acid and subsequent DNA hypomethylation may be involved in gastric carcinogenesis. Epidemiological and nutritional studies have indicated that folate status modulates the risk of developing cancers. AIMS: To investigate whether folic acid plays an important role in the chemoprevention of gastric carcinogenesis induced by N-ethyl-N-nitrosoguanidine (ENNG) in beagles. METHODS: Sixteen male beagles were randomly divided into two groups: folic acid treated group and control group. In both groups beagles were fed ENNG 75 mg per day for eight months and in the treated group 20 mg folic acid was given to beagles for 15 months. Gastroscopy and biopsies were performed before and every 2-3 months after administration of ENNG until the end of the experiment. Histopathological lesions were diagnosed with regard to the criteria for human gastric mucosal biopsies. Serum and gastric mucosal tissue folic acid concentrations were measured. RESULTS: In the control group, all beagles developed gastric cancer (8/8) compared with only 3/8 in the folic acid treated group (p<0.05). Moreover, serum and gastric mucosal tissue folic acid concentrations were markedly elevated 15 months after folic acid administration. The difference was statistically significant between the two groups (p<0.05). CONCLUSIONS: Our results indicate that high dose folic acid plays an important role in the chemoprevention of gastric carcinogenesis induced by a chemical carcinogen ENNG in beagles.


Asunto(s)
Ácido Fólico/uso terapéutico , Metilnitronitrosoguanidina/análogos & derivados , Neoplasias Gástricas/prevención & control , Animales , Carcinógenos , Perros , Ácido Fólico/análisis , Mucosa Gástrica/química , Mucosa Gástrica/patología , Masculino , Radioinmunoensayo , Juego de Reactivos para Diagnóstico , Espectrofotometría , Neoplasias Gástricas/inducido químicamente , Neoplasias Gástricas/patología , Resultado del Tratamiento
14.
Aliment Pharmacol Ther ; 15(12): 1975-9, 2001 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-11736729

RESUMEN

BACKGROUND: The metronidazole resistance of Helicobacter pylori strains has increased rapidly. AIM: To evaluate the efficacy and safety of new 1-week regimens containing ranitidine bismuth citrate, furazolidone and either amoxicillin or tetracycline. METHODS: One hundred and twenty patients with H. pylori-positive inactive duodenal ulcer or non-ulcer dyspepsia diagnosed by endoscopy were recruited randomly to receive one of two regimens for 7 days: ranitidine bismuth citrate, 350 mg b.d., furazolidone, 100 mg b.d., and either amoxicillin, 1000 mg b.d. (n=60), or tetracycline, 500 mg b.d. (n=60). H. pylori infection was identified by rapid urease testing and histology. 13C-Urea breath test was performed to evaluate the cure of H. pylori infection at least 4 weeks after completion of triple therapy. RESULTS: The eradication rates of H. pylori by ranitidine bismuth citrate-furazolidone-amoxicillin and ranitidine bismuth citrate-furazolidone-tetracycline regimens were 82% and 85% (P > 0.05), respectively, by intention-to-treat analysis, and 85% and 91% (P > 0.05), respectively, by per protocol analysis. Adverse effects were mild in both ranitidine bismuth citrate-furazolidone-amoxicillin and ranitidine bismuth citrate-furazolidone-tetracycline groups. CONCLUSIONS: One-week regimens containing ranitidine bismuth citrate, furazolidone and amoxicillin or tetracycline are well tolerated and effective for the eradication of H. pylori.


Asunto(s)
Antiulcerosos/uso terapéutico , Bismuto/uso terapéutico , Infecciones por Helicobacter/tratamiento farmacológico , Helicobacter pylori/efectos de los fármacos , Ranitidina/análogos & derivados , Ranitidina/uso terapéutico , Adolescente , Adulto , Anciano , Amoxicilina/uso terapéutico , Antibacterianos/uso terapéutico , Antiinfecciosos Locales/uso terapéutico , Antiulcerosos/efectos adversos , Bismuto/efectos adversos , Diarrea/inducido químicamente , Mareo/inducido químicamente , Método Doble Ciego , Quimioterapia Combinada , Exantema/inducido químicamente , Femenino , Furazolidona/uso terapéutico , Infecciones por Helicobacter/prevención & control , Humanos , Masculino , Persona de Mediana Edad , Penicilinas/uso terapéutico , Estudios Prospectivos , Prurito/inducido químicamente , Ranitidina/efectos adversos , Tetraciclina/uso terapéutico , Resultado del Tratamiento , Vómitos/inducido químicamente
15.
J Gastroenterol Hepatol ; 16(9): 960-8, 2001 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-11595058

RESUMEN

DNA methylation is the main epigenetic modification in humans. The methylation of promoter inhibits the transcription in most genes. In normal tissues, isolated CpG dinucleotides in bulk chromatin are often methylated, whereas cytosines in CpG islands are unmethylated. In neoplasms including gastrointestinal cancer, this pattern of methylation is commonly reversed. The alteration of DNA methylation plays a key role in the process of carcinogenesis. The gastrointestinal carcinogenesis is suggested to be associated with the decrease of total genomic DNA methylation; hypomethylation of certain specific oncogenes such as c-myc, c-Ha-ras, c-fos and alpha-fetoprotein; and hypermethylation of the promoter of some tumor suppressor genes containing p16(INK4A), E-cadherin and hMLH1 genes. This review focuses on the analysis methods for methylation, studies for aberrant DNA methylation in gastrointestinal carcinogenesis, and the intervention changing methylation, including the treatment of 5-azacytidine, supplement of folate and gene therapy.


Asunto(s)
Transformación Celular Neoplásica/genética , Metilación de ADN , Neoplasias Gastrointestinales/genética , Proteínas Adaptadoras Transductoras de Señales , Animales , Proteínas Portadoras , Regulación Neoplásica de la Expresión Génica/fisiología , Genes Supresores/fisiología , Humanos , Homólogo 1 de la Proteína MutL , Proteínas de Neoplasias/genética , Proteínas Nucleares , Oncogenes/genética , Regiones Promotoras Genéticas/genética , Transcripción Genética/genética
16.
Int J Biochem Cell Biol ; 33(11): 1071-9, 2001 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11551823

RESUMEN

Gastrin17gly acts as a growth factor for the colonic mucosa. Studies of the receptor involved have generally been restricted to its binding properties, and no investigation of the structure of gastrin17gly receptors on human colorectal carcinoma cell lines has yet been reported. The aim of this study was to optimise the conditions for binding of gastrin17gly to the human colorectal carcinoma cell line DLD-1, and to investigate the structure of the receptor responsible. Binding of 125I[Met15]gastrin17gly to DLD-1 cells was measured in competition experiments with increasing concentrations of either gastrin17gly or gastrin17, or with single concentrations of gastrin receptor antagonists. The molecular weights of the gastrin17gly binding proteins were determined by gel electrophoresis and autoradiography after covalent cross-linking of 125I[Nle15]gastrin2,17gly to cells or membranes with disuccinimidyl suberate. The IC50 value for binding of gastrin17gly to DLD-1 cells was 2.1+/-0.4 microM. Binding was inhibited by the non-selective gastrin/cholecystokinin receptor antagonists proglumide and benzotript, but not by the cholecystokinin-A receptor antagonist L364,718, or the gastrin/cholecystokinin-B receptor antagonist L365,260. The molecular weight of the major gastrin binding protein on DLD-1 cells or membranes was 70,000. We conclude that the major gastrin17gly binding site on the human colorectal carcinoma cell line DLD-1 is clearly distinct from the cholecystokinin-A and gastrin/cholecystokinin-B receptors, but is similar in some respects to the gastrin/cholecystokinin-C receptor.


Asunto(s)
Neoplasias Colorrectales/metabolismo , Gastrinas/metabolismo , Receptores de Colecistoquinina/química , Receptores de Colecistoquinina/metabolismo , Autorradiografía , Unión Competitiva , Membrana Celular/química , Membrana Celular/metabolismo , Colecistoquinina/antagonistas & inhibidores , Colecistoquinina/metabolismo , Neoplasias Colorrectales/patología , Reactivos de Enlaces Cruzados/metabolismo , Electroforesis en Gel de Poliacrilamida , Humanos , Peso Molecular , Receptores de Colecistoquinina/análisis , Receptores de Colecistoquinina/antagonistas & inhibidores , Factores de Tiempo , Células Tumorales Cultivadas
17.
J Clin Pathol ; 54(5): 367-70, 2001 May.
Artículo en Inglés | MEDLINE | ID: mdl-11328835

RESUMEN

AIM-Atrophy and intestinal metaplasia (IM) as precancerous conditions consistently begin in the antrum and are most severe along the lesser curvature. The aim of this study was to investigate discrepancies in the prevalence, the severity of atrophy, and IM in antral mucosa of Helicobacter pylori infected gastritis and difference in age of onset among Chinese and Dutch patients. METHODS-Two hundred and sixty five Chinese patients and 261 Dutch patients with H pylori infection were enrolled. The degrees of atrophy and IM were graded according to the updated Sydney system. RESULTS-The overall prevalences of atrophy and IM were lower in Dutch patients (42% and 26%, respectively) than in Chinese patients (52% and 32%, respectively). Only the difference in atrophy reached significance (p = 0.028). However, in both Chinese and Dutch patients, the degrees of atrophy and IM were low and severe degrees were rare. The mean ages of Chinese and Dutch patients with atrophy and IM were higher than those without atrophy and IM (with atrophy (Chinese patients): mean, 42.12; SD, 9.80; with IM (Chinese patients): mean, 42.56; SD, 9.96; with atrophy (Dutch patients): mean, 55.16; SD, 12.20; with IM (Dutch patients): mean, 57.79; SD, 11.13; without atrophy (Chinese patients): mean, 39.71; SD, 10.16; without IM (Chinese patients): mean, 40.19; SD, 9.99; without atrophy (Dutch patients): mean, 45.70; SD, 12.44; without IM (Dutch patients): mean, 46.89; SD, 12.68). Atrophy and IM occurred earlier and were more severe in Chinese patients, with both reaching a peak value in patients over 60 years. CONCLUSIONS-There are geographical differences in the prevalence and severity of H pylori infected gastritis, in particular with respect to atrophy and IM, which suggests that infection with H pylori occurs earlier in life and has a higher prevalence in CHINA:


Asunto(s)
Gastritis/etnología , Infecciones por Helicobacter/etnología , Helicobacter pylori , Lesiones Precancerosas/etnología , Neoplasias Gástricas/etnología , Adolescente , Adulto , Distribución por Edad , Edad de Inicio , Anciano , Atrofia/etnología , China/epidemiología , Femenino , Gastritis/complicaciones , Infecciones por Helicobacter/complicaciones , Humanos , Masculino , Metaplasia/etnología , Persona de Mediana Edad , Países Bajos/epidemiología , Lesiones Precancerosas/etiología , Prevalencia , Estómago/patología , Neoplasias Gástricas/etiología
19.
Aliment Pharmacol Ther ; 15(1): 81-6, 2001 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-11136281

RESUMEN

BACKGROUND: Short-term proton pump inhibitor-based triple therapies for the eradication of Helicobacter pylori are used widely. The eradication rates vary greatly from country to country and from region to region. AIM: To assess the efficacy at eradicating H. pylori of 1-week regimens containing three medications: omeprazole (O) or colloidal bismuth subcitrate (B), furazolidone (F) or metronidazole (M), and amoxicillin (A) or clarithromycin (C). METHODS: A multicentre study involving 20 hospitals in different regions of China. A total of 892 patients with H. pylori-positive non-ulcer dyspepsia or healed duodenal ulcer confirmed by endoscopy were recruited to receive, randomly, one of four regimens: OMC, OFC, OFA, and BFC, b.d. for 7 days. 13C-urea breath test was performed 4-8 weeks after completion of treatment. RESULTS: The eradication rates with per protocol/intention-to-treat analyses were: OMC (n=217/219) 66%/65%; OFC (n=227/229) 69%/69%; OFA (n=223/225) 87%/86%; and BFC (n=214/219) 80%/78%. The eradication rate (per protocol analysis) in duodenal ulcer (79%) was higher than that in non-ulcer dyspepsia (73%, P=0.033). Patient compliance was good. The adverse events of the four regimens were mild, and mainly gastrointestinal. CONCLUSIONS: The omeprazole, furazolidine and amoxicillin regimen achieves a high H. pylori eradication rate in different geographical regions of China.


Asunto(s)
Helicobacter pylori/efectos de los fármacos , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Amoxicilina/administración & dosificación , Pruebas Respiratorias , Claritromicina/administración & dosificación , Quimioterapia Combinada , Femenino , Furazolidona/administración & dosificación , Humanos , Masculino , Metronidazol/administración & dosificación , Persona de Mediana Edad , Omeprazol/administración & dosificación , Estudios Prospectivos
20.
Aliment Pharmacol Ther ; 14(11): 1519-22, 2000 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11069324

RESUMEN

BACKGROUND: In our previous study, a triple therapy using tripotassium dicitrato bismuthate (TDB), josamycin and furazolidone achieved a suboptimal cure rate of Helicobacter pylori infection. AIM: To investigate whether the addition of an antisecretory agent raises the cure rate using this regimen. METHODS: One hundred and twenty H. pylori positive patients with peptic ulcer disease or functional dyspepsia were randomly assigned to receive 1-week quadruple therapy of TDB 240 mg b.d., furazolidone 100 mg b.d., josamycin 1000 mg b.d. and famotidine 20 mg b.d. (BFJF group), or triple therapy of TDB 240 mg b.d., furazolidone 100 mg b.d. and clarithromycin 250 mg b.d. (BFC group). H. pylori status was assessed by histology and culture of gastric biopsy specimens before and at least 4 weeks after completion of therapy. RESULTS: Seven patients (three in the BFJF group and four in the BFC group) dropped out. Eradication rates (intention-to-treat/per protocol) were 90%/95% in the BFJF group and 82%/88% in the BFC group, respectively (P > 0.05). Duodenal ulcer healing rates were 94% (16/17) in the BFJF group and 80% (20/25) in the BFC group, respectively (P > 0.05). Mild side-effects occurred in 11 (18%) patients in the BFJF group and 10 (17%) in the BFC group (P > 0.05). CONCLUSIONS: One-week quadruple therapy consisting of TDB, furazolidone, josamycin and famotidine achieves a high cure rate of H. pylori infection.


Asunto(s)
Famotidina/uso terapéutico , Furazolidona/uso terapéutico , Infecciones por Helicobacter/tratamiento farmacológico , Helicobacter pylori , Josamicina/uso terapéutico , Compuestos Organometálicos/uso terapéutico , Adulto , Anciano , Antibacterianos/administración & dosificación , Antibacterianos/uso terapéutico , Antiinfecciosos Locales/administración & dosificación , Antiinfecciosos Locales/uso terapéutico , Antiulcerosos/administración & dosificación , Antiulcerosos/uso terapéutico , Quimioterapia Combinada , Úlcera Duodenal/tratamiento farmacológico , Famotidina/administración & dosificación , Femenino , Furazolidona/administración & dosificación , Infecciones por Helicobacter/patología , Humanos , Josamicina/administración & dosificación , Masculino , Persona de Mediana Edad , Compuestos Organometálicos/administración & dosificación , Resultado del Tratamiento
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...