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1.
Genes Dev ; 28(1): 14-9, 2014 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-24395245

RESUMEN

The kinetics with which promoter-proximal paused RNA polymerase II (Pol II) undergoes premature termination versus productive elongation is central to understanding underlying mechanisms of metazoan transcription regulation. To assess the fate of Pol II quantitatively, we tracked photoactivatable GFP-tagged Pol II at uninduced Hsp70 on polytene chromosomes and showed that Pol II is stably paused with a half-life of 5 min. Biochemical analysis of short nascent RNA from Hsp70 reveals that this half-life is determined by two comparable rates of productive elongation and premature termination of paused Pol II. Importantly, heat shock dramatically increases elongating Pol II without decreasing termination, indicating that regulation acts at the step of paused Pol II entry to productive elongation.


Asunto(s)
Proteínas de Drosophila/metabolismo , Drosophila melanogaster/enzimología , Drosophila melanogaster/genética , Regulación de la Expresión Génica , Proteínas HSP70 de Choque Térmico/metabolismo , Regiones Promotoras Genéticas/fisiología , ARN Polimerasa II/metabolismo , Animales , Proteínas de Drosophila/genética , Proteínas HSP70 de Choque Térmico/genética , Cinética , ARN Polimerasa II/genética , Transgenes
2.
Gastroenterology ; 157(3): 637-646.e4, 2019 09.
Artículo en Inglés | MEDLINE | ID: mdl-31095949

RESUMEN

BACKGROUND & AIMS: Enteropathy and small-intestinal ulcers are common adverse effects of nonsteroidal anti-inflammatory drugs such as acetylsalicylic acid (ASA). Safe, cytoprotective strategies are needed to reduce this risk. Specific bifidobacteria might have cytoprotective activities, but little is known about these effects in humans. We used serial video capsule endoscopy (VCE) to assess the efficacy of a specific Bifidobacterium strain in healthy volunteers exposed to ASA. METHODS: We performed a single-site, double-blind, parallel-group, proof-of-concept analysis of 75 heathy volunteers given ASA (300 mg) daily for 6 weeks, from July 31 through October 24, 2017. The participants were randomly assigned (1:1) to groups given oral capsules of Bifidobacterium breve (Bif195) (≥5 × 1010 colony-forming units) or placebo daily for 8 weeks. Small-intestinal damage was analyzed by serial VCE at 6 visits. The area under the curve (AUC) for intestinal damage (Lewis score) and the AUC value for ulcers were the primary and first-ranked secondary end points of the trial, respectively. RESULTS: Efficacy data were obtained from 35 participants given Bif195 and 31 given placebo. The AUC for Lewis score was significantly lower in the Bif195 group (3040 ± 1340 arbitrary units) than the placebo group (4351 ± 3195) (P = .0376). The AUC for ulcer number was significantly lower in the Bif195 group (50.4 ± 53.1 arbitrary units) than in the placebo group (75.2 ± 85.3 arbitrary units) (P = .0258). Twelve adverse events were reported from the Bif195 group and 20 from the placebo group. None of the events was determined to be related to Bif195 intake. CONCLUSIONS: In a randomized, double-blind trial of healthy volunteers, we found oral Bif195 to safely reduce the risk of small-intestinal enteropathy caused by ASA. ClinicalTrials.gov no: NCT03228589.


Asunto(s)
Antiinflamatorios no Esteroideos/efectos adversos , Aspirina/efectos adversos , Bifidobacterium breve/crecimiento & desarrollo , Microbioma Gastrointestinal , Intestino Delgado/efectos de los fármacos , Intestino Delgado/microbiología , Probióticos/administración & dosificación , Úlcera/prevención & control , Adolescente , Adulto , Endoscopía Capsular , Método Doble Ciego , Femenino , Voluntarios Sanos , Humanos , Intestino Delgado/patología , Irlanda , Masculino , Probióticos/efectos adversos , Factores de Tiempo , Úlcera/inducido químicamente , Úlcera/microbiología , Úlcera/patología , Adulto Joven
3.
Scand J Gastroenterol ; 55(7): 786-794, 2020 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-32544012

RESUMEN

SUMMARY: This study reviews the safety and efficacy of treatment with vedolizumab for patients with inflammatory bowel disease across 9 Irish hospitals. It generates valuable and timely real-world data on treatment outcomes to add to the existing evidence base. Our population represents a refractory cohort with most patients previously exposed to at least one anti-TNFa agent and expressing an inflammatory phenotype. Results are reassuringly similar to larger international studies with additional insights into potential predictors of treatment response. This study further supports the safety and efficacy of vedolizumab in the treatment of inflammatory bowel disease. Key SummaryVedolizumab has growing real world data on its safety and efficacy in the treatment of IBD. Data on predictors of response are lacking. Studies such as VARSITY require new real-world data to help identify the place VDZ will occupy in the treatment algorithm for IBDThis study provides national Irish data on the safety and efficacy of VDZ in the treatment of IBD. It gives insight into various predictors of response for both UC and CD. It strengthens the available body of evidence on the use of VDZ and helps us determine its position on the treatment algorithm.


Asunto(s)
Anticuerpos Monoclonales Humanizados/uso terapéutico , Colitis Ulcerosa/tratamiento farmacológico , Enfermedad de Crohn/tratamiento farmacológico , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Estudios de Cohortes , Femenino , Humanos , Irlanda , Estimación de Kaplan-Meier , Modelos Logísticos , Masculino , Persona de Mediana Edad , Análisis Multivariante , Inducción de Remisión , Resultado del Tratamiento , Adulto Joven
4.
Dis Esophagus ; 33(10)2020 Oct 12.
Artículo en Inglés | MEDLINE | ID: mdl-32193532

RESUMEN

Barrett's esophagus (BE) is the main pathological precursor of esophageal adenocarcinoma (EAC). Progression to high-grade dysplasia (HGD) or EAC from nondysplastic BE (NDBE), low-grade dysplasia (LGD) and indefinite for dysplasia (IND) varies widely between population-based studies and specialized centers for many reasons, principally the rigor of the biopsy protocol and the accuracy of pathologic definition. In the Republic of Ireland, a multicenter prospective registry and bioresource (RIBBON) was established in 2011 involving six academic medical centers, and this paper represents the first report from this network. A detailed clinical, endoscopic and pathologic database registered 3,557 patients. BE was defined strictly by both endoscopic evidence of Barrett's epithelium and the presence of specialized intestinal metaplasia (SIM). A prospective web-based database was used to gather information with initial and follow-up data abstracted by a data manager at each site. A total of 2,244 patients, 1,925 with no dysplasia, were included with complete follow-up. The median age at diagnosis was 60.5 with a 2.1:1 male to female ratio and a median follow-up time of 2.7 years (IQR 1.19-4.04), and 6609.25 person years. In this time period, 125 (5.57%) progressed to HGD/EAC, with 74 (3.3%) after 1 year of follow-up and 38 (1.69%) developed EAC, with 20 (0.89%) beyond 1 year. The overall incidence of HGD/EAC was 1.89% per year; 1.16% if the first year is excluded. The risk of progression to EAC alone overall was 0.57% per year, 0.31% excluding the first year, and 0.21% in the 1,925 patients who had SIM alone at diagnosis. Low-grade dysplasia (LGD) progressed to HGD/EAC in 31% of patients, a progression rate of 12.96% per year, 6.71% with the first year excluded. In a national collaboration of academic centers in Ireland, the progression rate for NDBE was similar to recent population studies. Almost one in two who progressed was evident within 1 year. Crucially, LGD diagnosed and confirmed by specialist gastrointestinal pathologists represents truly high-risk disease, highlighting the importance of expertise in diagnosis and management, and providing indirect support for ablative therapies in this context.


Asunto(s)
Esófago de Barrett , Neoplasias Esofágicas , Lesiones Precancerosas , Esófago de Barrett/epidemiología , Progresión de la Enfermedad , Neoplasias Esofágicas/epidemiología , Neoplasias Esofágicas/etiología , Femenino , Humanos , Irlanda/epidemiología , Masculino , Lesiones Precancerosas/epidemiología , Sistema de Registros
5.
Mol Cell ; 40(6): 965-75, 2010 Dec 22.
Artículo en Inglés | MEDLINE | ID: mdl-21172661

RESUMEN

Chromatin immunoprecipitation (ChIP) studies provide snapshots of factors on chromatin in cell populations. Here, we use live-cell imaging to examine at high temporal resolution the recruitment and dynamics of transcription factors to the inducible Hsp70 loci in individual Drosophila salivary gland nuclei. Recruitment of the master regulator, HSF, is first detected within 20 s of gene activation; the timing of its recruitment resolves from RNA polymerase II and P-TEFb, and these factors resolve from Spt6 and Topo I. Remarkably, the recruitment of each factor is highly synchronous between different cells. In addition, fluorescence recovery after photobleaching (FRAP) analyses show that the entry and exit of multiple factors are progressively constrained upon gene activation, suggesting the gradual formation of a transcription compartment. Furthermore, we demonstrate that poly(ADP-ribose) (PAR) polymerase activity is required to maintain the transcription compartment. We propose that PAR polymers locally retain factors in a transcription compartment.


Asunto(s)
Proteínas de Unión al ADN/metabolismo , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/citología , Drosophila melanogaster/metabolismo , Proteínas HSP70 de Choque Térmico/metabolismo , Factor B de Elongación Transcripcional Positiva/metabolismo , ARN Polimerasa II/metabolismo , Glándulas Salivales/citología , Factores de Transcripción/metabolismo , Animales , Núcleo Celular/metabolismo , Supervivencia Celular , Proteínas de Unión al ADN/genética , Proteínas de Drosophila/genética , Factores de Transcripción del Choque Térmico , Factor B de Elongación Transcripcional Positiva/genética , ARN Polimerasa II/genética , Glándulas Salivales/metabolismo , Factores de Tiempo , Factores de Transcripción/genética
7.
Br J Nutr ; 112(4): 638-46, 2014 Aug 28.
Artículo en Inglés | MEDLINE | ID: mdl-24967992

RESUMEN

In the present study, structural changes in the milk protein α-lactalbumin (α-LA) and its proteolysis were investigated for the potential formation of protein-fatty acid complexes during in vivo gastric digestion. Capsule endoscopy allowed visualisation of the digestion of the test drinks, with nasogastric tubes allowing sampling of the gastric contents. A total of ten healthy volunteers had nasogastric tubes inserted into the stomach and ingested test drinks containing 50 g/l of sucrose and 25 g/l of α-LA with and without 4 g/l of oleic acid (OA). The samples of gastric contents were collected for analysis at 3 min intervals. The results revealed a rapid decrease in the pH of the stomach of the subjects. The fasting pH of 2·31 (SD 1·19) increased to a pH maxima of pH 6·54 (SD 0·29) after ingestion, with a subsequent decrease to pH 2·22 (SD 1·91) after 21 min (n 8). Fluorescence spectroscopy and Fourier transform IR spectroscopy revealed partial protein unfolding, coinciding with the decrease in pH below the isoelectric point of α-LA. The activity of pepsin in the fasting state was found to be 39 (SD 12) units/ml of gastric juice. Rapid digestion of the protein occurred: after 15 min, no native protein was detected using SDS-PAGE; HPLC revealed the presence of small amounts of native protein after 24 min of gastric digestion. Mirocam® capsule endoscopy imaging and video clips (see the online supplementary material) revealed that gastric peristalsis resulted in a heterogeneous mixture during gastric digestion. Unfolding of α-LA was observed during gastric transit; however, there was no evidence of a cytotoxic complex being formed between α-LA and OA.


Asunto(s)
Digestión , Jugo Gástrico/metabolismo , Mucosa Gástrica/metabolismo , Lactalbúmina/metabolismo , Peristaltismo , Estómago/fisiología , Adulto , Animales , Antineoplásicos/farmacología , Endoscopía Capsular , Bovinos , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Femenino , Jugo Gástrico/enzimología , Mucosa Gástrica/enzimología , Humanos , Intubación Gastrointestinal , Lactalbúmina/efectos adversos , Lactalbúmina/química , Lactalbúmina/farmacología , Masculino , Ácido Oléico/química , Ácido Oléico/metabolismo , Ácido Oléico/farmacología , Ácidos Oléicos/farmacología , Fragmentos de Péptidos/química , Fragmentos de Péptidos/metabolismo , Fragmentos de Péptidos/farmacología , Desplegamiento Proteico
8.
Eur J Case Rep Intern Med ; 11(1): 004219, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38223286

RESUMEN

Introduction: Hereditary haemorrhagic telangiectasia (HHT) is a rare multi-organ vascular disease. It is characterised by mucocutaneous telangiectasia, epistaxis, and arteriovenous malformations. Some 70% of patients with HHT are thought to have issues with gastrointestinal (GI) bleeding. Traditional management of GI bleeding in HHT includes monitoring for iron deficiency anaemia, iron replacement, antifibrinolytic therapy and control of identifiable bleeding sites with argon photocoagulation during gastrointestinal endoscopy. Blood transfusion may also be required. Case description: Our case describes a man in his 40s with confirmed HHT, with transfusion-dependent anaemia secondary to GI bleeding. He was commenced on fortnightly bevacizumab (5 mg/kg) for 12 weeks in an attempt to reduce his blood transfusion requirement and manage his anaemia. In the months prior to starting bevacizumab, our patient's transfusion requirement ranged from 3-5 units of packed red cells per month to maintain an Hb >8 g/dl. He had a marked improvement in his symptoms within the first month of treatment and did not require any further blood transfusion during the three months of treatment. He was given one further IV iron infusion in the final month of his 3-month bevacizumab treatment and did not experience any adverse side effects from bevacizumab. Discussion: HHT results from alterations to genes which encode proteins involved in blood vessel formation. This provides the rationale for using anti VEGF drugs such as bevacizumab. Current evidence for this treatment approach is limited. Conclusion: Bevacizumab can be an effective treatment option in patients with HHT refractory to traditional management. LEARNING POINTS: Gastrointestinal bleeding in hereditary haemorrhagic telangiectasia can be difficult to treat.Bevacizumab, an anti-vascular endothelial growth factor, can be used to treat refractory anaemia secondary to gastrointestinal bleeding in hereditary haemorrhagic telangiectasia.

9.
Sci Rep ; 14(1): 3725, 2024 02 14.
Artículo en Inglés | MEDLINE | ID: mdl-38355674

RESUMEN

Stress and sleep are linked with overall well-being. Bifidobacterium longum 1714 has been shown to influence stress responses and modulate neural responses during social stress, and influence sleep quality during examination stress in healthy adults. Here, we explored the ability of this strain to alter sleep quality in adults using subjective and objective measures. Eighty-nine adults (18-45y) with impaired sleep quality assessed with the Pittsburgh Sleep Quality Index (PSQI) and with a global score ≥ 5 were randomized to receive B. longum 1714 or placebo daily for eight weeks. Assessing the effect of the strain on PSQI global score was the primary objective. Secondary objectives assessed sleep quality and well-being subjectively and sleep parameters using actigraphy objectively. While PSQI global score improved in both groups, B. longum 1714 significantly improved the PSQI component of sleep quality (p < 0.05) and daytime dysfunction due to sleepiness (p < 0.05) after 4 weeks and social functioning (p < 0.05) and energy/vitality (p < 0.05) after 8 weeks, compared to placebo. No significant effect on actigraphy measures were observed. The 1714 strain had a mild effect on sleep, demonstrated by a faster improvement in sleep quality at week 4 compared to placebo, although overall improvements after 8 weeks were similar in both groups. B. longum 1714 improved social functioning and increased energy/vitality in line with previous work that showed the strain modulated neural activity which correlated with enhanced vitality/reduced mental fatigue (ClinicalTrials.gov: NCT04167475).


Asunto(s)
Bifidobacterium longum , Calidad del Sueño , Adulto , Humanos , Sueño , Actigrafía , Método Doble Ciego , Resultado del Tratamiento
10.
Eur J Gastroenterol Hepatol ; 36(8): 1000-1009, 2024 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-38829956

RESUMEN

BACKGROUND: There has been an increase in resistance to many of the antimicrobials used to treat Helicobacter pylori ( H. pylori ) nationally and internationally. Primary clarithromycin resistance and dual clarithromycin and metronidazole resistance are high in Ireland. These trends call for an evaluation of best-practice management strategies. OBJECTIVE: The objective of this study was to revise the recommendations for the management of H. pylori infection in adult patients in the Irish healthcare setting. METHODS: The Irish H. pylori working group (IHPWG) was established in 2016 and reconvened in 2023 to evaluate the most up-to-date literature on H. pylori diagnosis, eradication rates and antimicrobial resistance. The 'GRADE' approach was then used to rate the quality of available evidence and grade the resulting recommendations. RESULTS: The Irish H. pylori working group agreed on 14 consensus statements. Key recommendations include (1) routine antimicrobial susceptibility testing to guide therapy is no longer recommended other than for clarithromycin susceptibility testing for first-line treatment (statements 6 and 9), (2) clarithromycin triple therapy should only be prescribed as first-line therapy in cases where clarithromycin susceptibility has been confirmed (statement 9), (3) bismuth quadruple therapy (proton pump inhibitor, bismuth, metronidazole, tetracycline) is the recommended first-line therapy if clarithromycin resistance is unknown or confirmed (statement 10), (4) bismuth quadruple therapy with a proton pump inhibitor, levofloxacin and amoxicillin is the recommended second-line treatment (statement 11) and (5) rifabutin amoxicillin triple therapy is the recommend rescue therapy (statement 12). CONCLUSION: These recommendations are intended to provide the most relevant current best-practice guidelines for the management of H. pylori infection in adults in Ireland.


Asunto(s)
Antibacterianos , Claritromicina , Quimioterapia Combinada , Infecciones por Helicobacter , Helicobacter pylori , Inhibidores de la Bomba de Protones , Humanos , Infecciones por Helicobacter/tratamiento farmacológico , Infecciones por Helicobacter/diagnóstico , Helicobacter pylori/efectos de los fármacos , Irlanda , Antibacterianos/uso terapéutico , Adulto , Inhibidores de la Bomba de Protones/uso terapéutico , Claritromicina/uso terapéutico , Metronidazol/uso terapéutico , Consenso , Farmacorresistencia Bacteriana , Pruebas de Sensibilidad Microbiana , Resultado del Tratamiento , Bismuto/uso terapéutico
11.
Dig Dis Sci ; 56(5): 1524-34, 2011 May.
Artículo en Inglés | MEDLINE | ID: mdl-21046243

RESUMEN

BACKGROUND: Experimental and clinical studies suggest an association between small intestinal bacterial overgrowth (SIBO) and nonalcoholic steatohepatitis (NASH). Liver injury and fibrosis could be related to exposure to bacterial products of intestinal origin and, most notably, endotoxin, including lipopolysaccharide (LPS). AIM: To compare the prevalence of SIBO and its relationships to LPS receptor levels and systemic cytokines in NASH patients and healthy control subjects. METHODS: Eighteen NASH patients (eight males) and 16 age-matched and gender-matched healthy volunteers were studied. SIBO was assessed by the lactulose breath hydrogen test (LHBT), plasma lipopolysaccharide binding protein (LBP) levels by ELISA, and expression (as a percentage) of TLR-2 and 4 on CD14-positive cells by flow cytometry. Pro-inflammatory cytokines (IL-1ß, IL-6, IL-8, and TNF-α) were measured in plasma. RESULTS: SIBO was more common in NASH patients than control subjects (77.78% vs. 31.25%; P < 0.0001). LBP levels and TLR-2 expression were similar in both groups, TLR-4/MD-2 expression on CD14 positive cells was higher among NASH patients: expression, mean ± SEM, NASH vs. control: 20.95 ± 2.91% vs. 12.73 ± 2.29%, P < 0.05. Among the examined cytokines, only IL-8 levels were significantly higher in patients than control (P = 0.04) and correlated positively with TLR-4 expression (r = 0.5123, P = 0.036). CONCLUSION: NASH patients have a higher prevalence of small intestinal bacterial overgrowth which is associated with enhanced expression of TLR-4 and release of IL-8. SIBO may have an important role in NASH through interactions with TLR-4 and induction of the pro-inflammatory cytokine, IL-8.


Asunto(s)
Hígado Graso/complicaciones , Regulación de la Expresión Génica/fisiología , Interleucina-8/sangre , Intestino Delgado/microbiología , Receptor Toll-Like 4/metabolismo , Proteínas de Fase Aguda/genética , Proteínas de Fase Aguda/metabolismo , Adulto , Pruebas Respiratorias , Proteínas Portadoras/genética , Proteínas Portadoras/metabolismo , Femenino , Humanos , Interleucina-8/genética , Interleucina-8/metabolismo , Lactulosa/metabolismo , Masculino , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/metabolismo , Persona de Mediana Edad , Receptor Toll-Like 4/genética
12.
Front Microbiol ; 12: 715863, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34408741

RESUMEN

Spore-based probiotics offer important advantages over other probiotics as they can survive the harsh gastric conditions of the stomach and bile salts in the small intestine, ultimately germinating in the digestive tract. A novel clinical trial in 11 ileostomy participants was conducted to directly investigate the presence and germination of the probiotic strain Bacillus subtilis DE111® in the small intestine. Three hours following ingestion of DE111®, B. subtilis spores (6.4 × 104 ± 1.3 × 105 CFU/g effluent dry weight) and vegetative cells (4.7 × 104 ± 1.1 × 105 CFU/g effluent dry weight) began to appear in the ileum effluent. Six hours after ingestion, spore concentration increased to 9.7 × 107 ± 8.1 × 107 CFU/g and remained constant to the final time point of 8 h. Vegetative cells reached a concentration of 7.3 × 107 ± 1.4 × 108 CFU/g at 7 h following ingestion. These results reveal orally ingested B. subtilis DE111® spores are able to remain viable during transit through the stomach and germinate in the small intestine of humans within 3 h of ingestion.

13.
Front Med (Lausanne) ; 8: 656493, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34513857

RESUMEN

Background and Study Aims: Deep learning (DL) for video capsule endoscopy (VCE) is an emerging research field. It has shown high accuracy for the detection of Crohn's disease (CD) ulcers. Non-steroidal anti-inflammatory drugs (NSAIDS) are commonly used medications. In the small bowel, NSAIDs may cause a variety of gastrointestinal adverse events including NSAID-induced ulcers. These ulcers are the most important differential diagnosis for small bowel ulcers in patients evaluated for suspected CD. We evaluated a DL network that was trained using CD VCE ulcer images and evaluated its performance for NSAID ulcers. Patients and Methods: The network was trained using CD ulcers and normal mucosa from a large image bank created from VCE of diagnosed CD patients. NSAIDs-induced enteropathy images were extracted from the prospective Bifidobacterium breve (BIf95) trial dataset. All images were acquired from studies performed using PillCam SBIII. The area under the receiver operating curve (AUC) was used as a metric. We compared the network's AUC for detecting NSAID ulcers to that of detecting CD ulcers. Results: Overall, the CD training dataset included 17,640 CE images. The NSAIDs testing dataset included 1,605 CE images. The DL network exhibited an AUC of 0.97 (95% CI 0.97-0.98) for identifying images with NSAID mucosal ulcers. The diagnostic accuracy was similar to that obtained for CD related ulcers (AUC 0.94-0.99). Conclusions: A network trained on VCE CD ulcers similarly identified NSAID findings. As deep learning is transforming gastrointestinal endoscopy, this result should be taken into consideration in the future design and analysis of VCE deep learning applications.

14.
Mol Biol Cell ; 18(4): 1179-86, 2007 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-17251548

RESUMEN

Similar to their human counterparts, the Drosophila Rbf1 and Rbf2 Retinoblastoma family members control cell cycle and developmentally regulated gene expression. Increasing evidence suggests that Rbf proteins rely on multiprotein complexes to control target gene transcription. We show here that the developmentally regulated COP9 signalosome (CSN) physically interacts with Rbf2 during embryogenesis. Furthermore, the CSN4 subunit of the COP9 signalosome co-occupies Rbf target gene promoters with Rbf1 and Rbf2, suggesting an active role for the COP9 signalosome in transcriptional regulation. The targeted knockdown of individual CSN subunits leads to diminished Rbf1 and Rbf2 levels and to altered cell cycle progression. The proteasome-mediated destruction of Rbf1 and Rbf2 is increased in cells and embryos with diminished COP9 activity, suggesting that the COP9 signalosome protects Rbf proteins during embryogenesis. Previous evidence has linked gene activation to protein turnover via the promoter-associated proteasome. Our findings suggest that Rbf repression may similarly involve the proteasome and the promoter-associated COP9 signalosome, serving to extend Rbf protein lifespan and enable appropriate programs of retinoblastoma gene control during development.


Asunto(s)
Proteínas de Drosophila/metabolismo , Complejos Multiproteicos/metabolismo , Péptido Hidrolasas/metabolismo , Proteínas Represoras/metabolismo , Animales , Complejo del Señalosoma COP9 , Ciclo Celular , Drosophila/embriología , Proteínas de Drosophila/genética , Embrión no Mamífero , Regulación del Desarrollo de la Expresión Génica , Regiones Promotoras Genéticas , Complejo de la Endopetidasa Proteasomal/metabolismo , Subunidades de Proteína , Proteínas Represoras/genética , Proteína de Retinoblastoma , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Activación Transcripcional
15.
Endosc Int Open ; 8(3): E396-E400, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-32118112

RESUMEN

Background and study aims Determining the etiology and location of gastrointestinal motility disorders can be challenging. A range of investigations targeting specific areas of gastrointestinal transit are available, but many provide clinical data for a given gastrointestinal region alone or for non-specific whole gut transit, and are otherwise of limited use. Video capsule endoscopy allows endoscopic visualisation of the entire gastrointestinal tract, and may also provide more specific data for regional transit time abnormalities. Patients and methods Data from video capsules ingested by 71 ambulatory healthy subjects were recorded and analyzed to determine gastric and small bowel transit times in the fasting state. Results Median, and interquartile range (IQR), gastric transit time was 22 (10-48) minutes, and median (IQR) small bowel transit time was 198.5 (157-240.5) minutes. Conclusion These data, for the first time to our knowledge, provide references for gastrointestinal transit times among healthy ambulatory subjects using video capsule endoscopy. This potentially strengthens clinical use of video capsule endoscopy in the investigation of patients with suspected gastrointestinal motility disorders.

16.
Endosc Int Open ; 8(2): E124-E132, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-32010744

RESUMEN

Background and study aims Electrochemotherapy is an anticancer treatment that uses electric pulses to facilitate uptake of chemotherapeutic drugs in tumor cells and has proven to have a high local cytotoxic effect with minimal adverse events. Electrochemotherapy has mostly been used in treatment of cutaneous metastases but development of a new endoscopic electrode device has made treatment of colorectal tumors possible. This first-in-man multicenter phase I study investigated safety and efficacy of electrochemotherapy using endoscopic electroporation in patients with colorectal tumors. Patients and methods Seven patients with colorectal tumors who were deemed ineligible for or had declined standard treatment were included. They were treated with bleomycin either intratumorally or intravenously and the electric pulses were delivered through the endoscopic electrode device. Safety and efficacy were assessed clinically and by scans immediately after treatment and adverse events were reported. Response was evaluated up to 6 months after treatment by scans (magnetic resonance imaging or computed tomography) and endoscopic examinations. Results Seven patients aged 62 to 88 years with multiple comorbidities were included and had one or two treatments each. Post-treatment scans showed tumor responses in the treated areas and no damage to surrounding tissues. Only a few grade one adverse events were reported. Three patients had preoperative rectal bleeding, of which two reported cessation of bleeding and one reported decreased bleeding. Conclusion This first-in-man study shows that electrochemotherapy for colorectal tumors using the endoscopic electrode device can induce local tumor response and is safe also for fragile elderly patients with comorbidities.

17.
Endosc Int Open ; 7(11): E1379-E1385, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-31673608

RESUMEN

Background and study aims Small bowel capsule endoscopy [SBCE) has an established role in investigating suspected small bowel bleeding [SSBB). Identification of a biomarker to predict pathology would maximize utility of this valuable diagnostic modality. This study aimed to investigate if fecal immunochemical test [FIT) could predict likelihood of small bowel pathology on SBCE. Patients and methods Patients referred for SBCE to investigate anaemia or suspected small bowel bleeding were prospectively recruited. All patients had negative upper and lower endoscopy prior to referral. A FIT ≥ 45 ug Hb/g was considered positive. SBCE was positive if a potential source of SSBB was identified. The primary endpoint was correlation between FIT and positive SBCE. Secondary endpoints were correlation between anemia and SBCE and a combination of anemia plus FIT and SBCE. Results Fifty-one patients were included in the final study cohort. 29.4 % had a positive FIT, 33.3 % were anemic, and 25.5 % patients had significant SBCE findings. There was a statistically significant association between positive FIT and pathology on SBCE (OR 12, 95 % CI [2.8 - 51.9), P  = 0.001). Sensitivity and specificity of positive FIT in predicting SBCE findings were 69 % and 84 %, respectively. A normal Hb had an NPV of 83 % (OR 0.30, P  = 0.09). Combining Hb and FIT was statistically significant in predicting pathology on SBCE (OR 9.14, 67 % PPV, 82 % NPV, P  = 0.025). Conclusion FIT ≥ 45 ug Hb/g is a useful tool in predicting small bowel pathology on SBCE. Use of this biomarker alone, or in combination with serum haemoglobin, has value as a screening tool and may help to better triage patients referred for SBCE.

18.
Biochem Mol Biol Educ ; 46(5): 445-452, 2018 09.
Artículo en Inglés | MEDLINE | ID: mdl-30204283

RESUMEN

Exposure of organisms to high temperatures and various chemical and physical stressors can cause protein misfolding and aggregation. In turn, this can disrupt the functions of proteins, threatening both development and homeostasis. To overcome this, cells can initiate the highly conserved heat shock (HS) stress response pathway. In eukaryotes, this is a coordinated cellular response, in which the master HS activator, heat shock factor (HSF), is rapidly recruited to the HS protein genes, and triggers the recruitment of additional coactivator proteins that facilitate gene expression. This results in the production of HS proteins that function as nuclear and cytosolic molecular chaperones, to promote refolding of proteins and prevent aggregation and increase protein degradation pathways. Here, we describe a laboratory exercise in which students visualize and quantify Green Fluorescent Protein (GFP)-tagged HSF binding to the HS protein genes in living Drosophila salivary gland nuclei as an output of chemically induced protein misfolding. Students are assigned an array of chemicals, and using the scientific literature, predict impacts of these chemicals on protein folding. Students then test the effects of their chemicals by measuring GFP-tagged HSF binding to the HS genes in salivary glands using confocal microscopy. Designed for junior and senior level students in a cell/molecular biology course, this is a two-part lab, in which student work closely with an instructor to help familiarize them with developing hypotheses supported by scientific literature and testing these hypotheses by quantitating the levels of GFP-HSF binding, using confocal microscopy of living Drosophila cells. © 2018 International Union of Biochemistry and Molecular Biology, 46(5):445-452, 2018.


Asunto(s)
Proteínas HSP70 de Choque Térmico/química , Factores de Transcripción del Choque Térmico/química , Laboratorios , Biología Molecular/educación , Animales , Sitios de Unión , Drosophila , Proteínas HSP70 de Choque Térmico/metabolismo , Factores de Transcripción del Choque Térmico/metabolismo , Estudiantes
19.
BMC Nutr ; 4: 48, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-32153909

RESUMEN

BACKGROUND: Helicobacter pylori is the major cause of chronic gastritis, and considered as a risk factor for peptic ulcer and gastric cancer. The H. pylori standard antibiotic therapy fails in about 25-30% of cases, particularly because of the increasing occurrence of resistance to antibiotics. The aim of the current study was to investigate whether the strain Lactobacillus reuteri DSM17648 which has been previously shown to reduce Helicobacter pylori load additionally improves gastrointestinal symptoms in H. pylori positive subjects when used in a 28 days supplementation. METHODS: In a single-blinded, placebo controlled study 24 H. pylori-positive adults (13 females, 11 males; median age: 43.5) with mild dyspepsia (mean GSRS score: 11.82) received placebo for 28 days followed by Pylopass™ containing the L. reuteri DSM 17648 (2 × 1010 cells per day) for the following 28 days. After 28 days of Pylopass™ supplementation the change in H. pylori load was measured by 13C urea breath test (13C-UBT) and the change in symptoms were determined by the Gastrointestinal Symptom Rating Scale (GSRS). In addition, blood assessments were conducted to measure the physiological changes relevant in terms of safety. RESULTS: After a 28-day supplementation phase with Pylopass™ there was a trend for reduction of H. pylori load in 62.5% of the subjects and for the overall GSRS scores in 66.7% of subjects. The overall GSRS scores from baseline to day 56 following all 24 subjects undergoing the placebo phase followed by the Pylopass™ phase was significantly decreased (p = 0.005). The mean 13C-UBT δ value decreased by 22.5% during the Pylopass™ supplementation phase (- 3.14), while the mean 13C-UBT δ increased by 37.3% (+ 3.79) in the placebo phase. No side effects were reported in either study phase. CONCLUSION: The results demonstrated that L. reuteri DSM17648 has the potential to suppress H. pylori infection, and may lead to an improvement of H. pylori-associated gastro intestinal symptoms. Further studies with adequate power should be performed. TRIAL REGISTRATION: Clinicaltrials.gov: NCT02051348 (January 30, 2014).

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