Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 39
Filtrar
Más filtros

Banco de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
Neth Heart J ; 25(7-8): 419-428, 2017 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-28643297

RESUMEN

BACKGROUND: To eliminate some of the potential late limitations of permanent metallic stents, the bioresorbable coronary stents or 'bioresorbable vascular scaffolds' (BVS) have been developed. METHODS: We reviewed all currently available clinical data on BVS implantation. RESULTS: Since the 2015 position statement on the appropriateness of BVS in percutaneous coronary interventions, several large randomised trials have been presented. These have demonstrated that achieving adequate 1 and 2 year outcomes with these first-generation BVS is not straightforward. These first adequately powered studies in non-complex lesions showed worse results if standard implantation techniques were used for these relatively thick scaffolds. Post-hoc analyses hypothesise that outcomes similar to current drug-eluting stents are still possible if aggressive lesion preparation, adequate sizing and high-pressure postdilatation are implemented rigorously. As long as this has not been confirmed in prospective studies the usage should be restricted to experienced centres with continuous outcome monitoring. For more complex lesions, results are even more disappointing and usage should be discouraged. When developed, newer generation scaffolds with thinner struts or faster resorption rates are expected to improve outcomes. In the meantime prolonged dual antiplatelet therapy (DAPT, beyond one year) is recommended in an individualised approach for patients treated with current generation BVS. CONCLUSION: The new 2017 recommendations downgrade and limit the use of the current BVS to experienced centres within dedicated registries using the updated implantation protocol and advise the prolonged usage of DAPT. In line with these recommendations the manufacturer does not supply devices to the hospitals without such registries in place.

2.
Eur J Clin Microbiol Infect Dis ; 34(6): 1223-9, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-25717021

RESUMEN

Resistance to third-generation cephalosporins in Gram-negative bacteria is emerging in Asia. We report the prevalence and distribution of extended-spectrum beta-lactamase (ESBL), AmpC beta-lactamase and carbapenemase-coding genes in cefotaxime-resistant Enterobacteriaceae isolates from bloodstream infections (BSI) in Cambodia. All Enterobacteriaceae isolated from BSI in adult patients at Sihanouk Hospital Centre of HOPE, Phnom Penh, Cambodia (2007-2010) were assessed. Antimicrobial susceptibility testing was carried out by disc diffusion and MicroScan according to Clinical and Laboratory Standards Institute (CLSI) guidelines. Screening for ESBL, plasmidic AmpC and carbapenemase-coding genes was performed by multiplex polymerase chain reaction (PCR) sequencing assays. Identification of the ST131 clone was performed in all CTX-M-positive Escherichia coli, using PCR targeting the papB gene. Out of 183 Enterobacteriaceae, 91 (49.7 %) isolates (84 BSI episodes) were cefotaxime-resistant: E. coli (n = 68), Klebsiella pneumoniae (n = 17) and Enterobacter spp. (n = 6). Most episodes were community-acquired (66/84; 78.3 %). ESBLs were present in 89/91 (97.8 %) cefotaxime-resistant isolates: 86 (96.6 %) were CTX-M, mainly CTX-M-15 (n = 41) and CTX-M-14 (n = 21). CTX-M of group 1 were frequently associated with TEM and/or OXA-1/30 coding genes and with phenotypic combined resistance to ciprofloxacin, sulphamethoxazole-trimethoprim and gentamicin (39/50, 78.0 %). Plasmidic AmpC (CMY-2 and DHA-1 types) were found alone (n = 2) or in combination with ESBL (n = 4). Eighteen E. coli isolates were identified as B2-ST131-O25B: 11 (61.1 %) carried CTX-M-14. No carbapenemase-coding genes were detected. ESBL among Enterobacteriaceae from BSI in Cambodia is common, mainly associated with CTX-M-15 and CTX-M-14. These findings warrant urgent action for the containment of antibiotic resistance in Cambodia.


Asunto(s)
Antibacterianos/farmacología , Bacteriemia/epidemiología , Cefalosporinas/farmacología , Infecciones por Enterobacteriaceae/epidemiología , Enterobacteriaceae/enzimología , Resistencia betalactámica , beta-Lactamasas/genética , Adolescente , Adulto , Anciano , Bacteriemia/microbiología , Cambodia/epidemiología , Cefotaxima/farmacología , Enterobacteriaceae/genética , Enterobacteriaceae/aislamiento & purificación , Infecciones por Enterobacteriaceae/microbiología , Escherichia coli , Femenino , Humanos , Klebsiella pneumoniae , Masculino , Pruebas de Sensibilidad Microbiana , Persona de Mediana Edad , Reacción en Cadena de la Polimerasa Multiplex , Prevalencia , Estudios Prospectivos , Análisis de Secuencia de ADN , Adulto Joven
3.
Euro Surveill ; 18(39)2013 Sep 26.
Artículo en Inglés | MEDLINE | ID: mdl-24094060

RESUMEN

We report an increased number of Salmonella enterica Paratyphi A infections in adults in Cambodia. Between January 2011 and August 2013, 71 S. Paratyphi A isolates were recovered from blood cultures, representing a 44-fold increase compared to July 2007 to December 2010, while monthly numbers of cultures did not change. Infections with S. Typhi increased two-fold in the same period. Most cases came from the capital Phnom Penh. These findings warrant epidemiological investigation to support public health measures.


Asunto(s)
Fiebre Paratifoidea/diagnóstico , Fiebre Paratifoidea/epidemiología , Salmonella paratyphi A/aislamiento & purificación , Adolescente , Adulto , Antibacterianos/farmacología , Cambodia/epidemiología , Niño , Farmacorresistencia Bacteriana Múltiple , Femenino , Humanos , Incidencia , Masculino , Pruebas de Sensibilidad Microbiana , Persona de Mediana Edad , Fiebre Paratifoidea/tratamiento farmacológico , Fiebre Paratifoidea/microbiología , Vigilancia de la Población , Factores de Riesgo , Salmonella paratyphi A/efectos de los fármacos , Adulto Joven
5.
Br J Pharmacol ; 153(7): 1550-7, 2008 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-18204478

RESUMEN

BACKGROUND AND PURPOSE: The finding that obestatin, a peptide encoded by the ghrelin gene, opposes ghrelin's stimulatory effect on food intake and gastric emptying has been questioned. The effect of obestatin has been mostly investigated in fasted rodents, a condition associated with high blood levels of ghrelin which may mask the effect of obestatin. We therefore investigated the effect of obestatin on food intake, gastric emptying and gastric contractility in ghrelin knockout mice. EXPERIMENTAL APPROACH: The effect of obestatin on 6-h cumulative food intake was studied in fasted wildtype (ghrelin+/+) and ghrelin knockout (ghrelin-/-) mice. In both genotypes, the effect of obestatin and/or ghrelin was studied in vivo on gastric emptying measured with the (14)C-octanoic acid breath test and in vitro on neural responses elicited by electrical field stimulation (EFS) of fundic smooth muscle strips. KEY RESULTS: Administration of obestatin did not influence fasting-induced hyperphagia or gastric emptying in both genotypes. Injection of ghrelin accelerated gastric emptying in ghrelin+/+ and ghrelin-/- mice but the effect was not reversed by co-injection with obestatin. In fundic strips from ghrelin+/+ and ghrelin-/- mice, ghrelin increased EFS-induced contractions, but obestatin was without effect. However, co-administration with obestatin tended to reduce the excitatory effect of ghrelin in both genotypes. CONCLUSIONS AND IMPLICATIONS: In ghrelin-/- mice, obestatin failed to affect food intake and gastric motility. These results suggest that endogenous ghrelin does not mask the effect of obestatin and confirm that obestatin administered peripherally is not a major regulator of satiety signalling or gut motility.


Asunto(s)
Ingestión de Alimentos/efectos de los fármacos , Vaciamiento Gástrico/efectos de los fármacos , Ghrelina/farmacología , Animales , Pruebas Respiratorias , Caprilatos , Estudios Cruzados , Estimulación Eléctrica , Fundus Gástrico/efectos de los fármacos , Fundus Gástrico/metabolismo , Genotipo , Ghrelina/administración & dosificación , Ghrelina/genética , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Contracción Muscular/efectos de los fármacos , Contracción Muscular/fisiología , Respuesta de Saciedad/efectos de los fármacos , Respuesta de Saciedad/fisiología , Transducción de Señal/efectos de los fármacos , Transducción de Señal/fisiología
6.
Catheter Cardiovasc Interv ; 71(4): 518-23, 2008 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-18307223

RESUMEN

OBJECTIVES: To compare Angio-Seal (AS) and StarClose (SC) and manual compression (MC) on efficacy of hemostasis, complication rate, safety of early mobilization, and patient comfort. BACKGROUND: Closure of the femoral artery after cardiac catheterization can be obtained through different methods. Today, physicians can choose from a number of different devices to achieve arterial closure. METHODS: In a prospective trial 450 patients were randomized to AS, SC, or MC. Patients were mobilized 1 to 2 hr after device placement, and 6 hr after MC. Data were collected during hospital admission and by telephone at one month after hospital discharge. RESULTS: Devices were used in 138/150 allocated to AS and 124/150 allocated to SC patients (92% vs. 83%, P = 0.015) Patients with MC experienced more pain during sheath removal than patients receiving a device, and rated their period of bed rest as less comfortable. Oozing and need for pressure bandage at the puncture site were observed in 37 AS patients and 57 SC patients (25% vs. 38%, P = 0.002). Hematoma occurred in 15 AS patients, in 17 SC patients, and in 14 MC patients (11 vs. 14 vs. 9%, ns). CONCLUSION: There is no difference in safety between the three methods of arterial closure. SC was more often not used or successfully deployed. SC patients more often had continuing oozing. On patient comfort, closure devices performed better than MC. Early ambulation in patients with a closure device is safe. AS is the preferred method of arterial closure after cardiac catheterization.


Asunto(s)
Cateterismo Cardíaco/efectos adversos , Arteria Femoral , Hemorragia/prevención & control , Técnicas Hemostáticas , Presión , Punciones/efectos adversos , Anciano , Ambulación Precoz , Diseño de Equipo , Femenino , Hematoma/etiología , Hemorragia/etiología , Técnicas Hemostáticas/efectos adversos , Técnicas Hemostáticas/instrumentación , Humanos , Masculino , Persona de Mediana Edad , Dolor/etiología , Dimensión del Dolor , Satisfacción del Paciente , Estudios Prospectivos , Proyectos de Investigación , Factores de Tiempo , Resultado del Tratamiento
7.
Neth Heart J ; 16(9): 291-2, 2008 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-18827872

RESUMEN

PURPOSE: To explore the hypothesis that stent placement decreases dilator function of various arteries outside the stented segment and that angiotensin- (1-7) improves this function, and to assess the contribution of dilator signal compounds. A further objective was to test the hypothesis that on-stent delivery of Ang-(1-7) reduces neointima formation and improves endothelial function. METHODS: Abdominal aortic stenting or sham operation was performed in the rat four weeks after stenting and treatment with intravenous saline or Ang-(1-7) infusion (24 mug/kg/h); vasomotor function in isolated thoracic aorta and brachial and iliac artery was measured in organ baths. Furthermore, Ang-(1-7)-eluting stents were designed and placed in rat abdominal aorta. Neointima formation and aortic function were tested after four weeks. RESULTS: Relaxation of the thoracic aorta to metacholine was decreased after stenting compared with shams due to a decrease in nitric oxide-mediated response (67% reduction in maximal NO-dependent response). Ang-(1-7) restored the response mainly through increased prostaglandin- and possibly also endothelial-derived hyperpolarising factor-mediated relaxation. Relaxation in the brachial artery decreased after stenting (maximal response dropped by 50%), whilst contractions to phenylephrine increased. Ang-(1-7) normalised vasomotor function. Iliac artery function remained unaltered after stenting but Ang-(1-7) increased maximal relaxations by 65%. Delivery of Ang-(1-7) by means of a drug-eluting stent improved endothelial function. CONCLUSION: Stenting differentially affects dilator and contractile function in various arterial beds. Ang-(1-7) both improves dilator function and normalises contractile function. Delivery of protective peptides such as Ang-(1-7) from the stent is a new therapy option that merits further development and exploration. (Neth Heart J 2008;16:293-8.).

8.
Neurogastroenterol Motil ; 19(3): 211-7, 2007 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-17300291

RESUMEN

Obestatin has recently been discovered in the rat stomach. It is encoded by the ghrelin gene and has been claimed to be a functional opponent of ghrelin and to be the natural ligand of the GPR39 receptor. The latter could not be confirmed by Holst et al. (Endocrinology, 2006). Yet, in GPR39 knockout mice, gastric emptying is accelerated. We verified the effects of obestatin on gastric emptying and intestinal contractility in rodents. Gastric emptying was measured with the (14)C octanoic breath test in mice. In vitro, the effect of obestatin was studied on electrically stimulated and non-stimulated strips from the fundus and small intestine of mice and rats. Obestatin (60, 125, 250 nmol kg(-1)) did not affect gastric emptying parameters (T(half) and T(lag)) and did not inhibit the prokinetic effects of ghrelin. Mouse and rat intestinal and fundic smooth muscle strips did not respond to obestatin either in the absence or in the presence of electrical field stimulation. Obestatin (125 nmol kg(-1)) did not inhibit fasting-induced hyperphagia. Our results suggest that peripheral obestatin is not a satiety signal that plays a role in the regulation of gastric emptying and do not support the concept that obestatin is a physiological opponent of ghrelin.


Asunto(s)
Vaciamiento Gástrico/fisiología , Motilidad Gastrointestinal/fisiología , Músculo Liso/fisiología , Hormonas Peptídicas/metabolismo , Animales , Masculino , Ratones , Ratones Endogámicos C57BL , Contracción Muscular/fisiología , Ratas , Ratas Wistar
9.
Methods Mol Biol ; 1479: 43-55, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-27738925

RESUMEN

Microencapsulation processes may be divided into three steps, namely: incorporation of the bioactive substance in the matrix, dispersion of the matrix in droplets, and conversion in microcapsules. This contribution is focused on the second step and more specifically using the dripping approach to form droplets by extrusion of liquid through a nozzle. Different technologies of dripping are described, using as an example the production of alginate beads.


Asunto(s)
Alginatos/química , Composición de Medicamentos/métodos , Algoritmos , Cápsulas/química , Composición de Medicamentos/instrumentación , Diseño de Equipo , Ácido Glucurónico/química , Gravitación , Ácidos Hexurónicos/química , Microesferas , Tamaño de la Partícula , Electricidad Estática
10.
Endocrinology ; 147(6): 2634-42, 2006 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-16484325

RESUMEN

Ghrelin is an orexigenic peptide involved in the regulation of energy homeostasis. To investigate the role of ghrelin in the hyperphagia associated with uncontrolled streptozotocin-induced diabetes, food intake was followed in diabetic ghrelin knockout (ghrelin(-/-)) and control wild-type (ghrelin(+/+)) mice and diabetic Naval Medical Research Institute noninbred Swiss mice treated with either saline or the ghrelin receptor antagonist, D-Lys3-GH-releasing peptide-6 (D-Lys3-GHRP-6) for 5 d. In diabetic ghrelin(-/-) mice, hyperphagia was attenuated, and the maximal increase in food intake was 50% lower in mutant than in wild-type mice. The increased food intake observed during the light period (1000-1200 h) in ghrelin(+/+) mice was abolished in mutant mice. Diabetic ghrelin(-/-) mice lost 12.4% more body weight than ghrelin(+/+) mice. In diabetic ghrelin(+/+) mice, but not in ghrelin(-/-) mice, the number of neuropeptide Y (NPY)-immunoreactive neurons was significantly increased. Diabetic Naval Medical Research Institute noninbred Swiss mice were hyperphagic and had increased plasma ghrelin levels. Treatment with D-Lys3-GHRP-6 reduced daily food intake by 23% and reversed the increased food intake observed during the light period. The change in the number of NPY- (2.4-fold increase) and alpha-MSH (1.7-fold decrease)-immunoreactive hypothalamic neurons induced by diabetes was normalized by D-Lys3-GHRP-6 treatment. Our results suggest that enhanced NPY and reduced alpha-MSH expression are secondary to the release of ghrelin, which should be considered the underlying trigger of hyperphagia associated with uncontrolled diabetes.


Asunto(s)
Diabetes Mellitus Experimental/complicaciones , Hiperfagia/etiología , Hormonas Peptídicas/fisiología , Animales , Núcleo Arqueado del Hipotálamo/fisiología , Glucemia/análisis , Peso Corporal , Ghrelina , Glucagón/sangre , Masculino , Ratones , Ratones Endogámicos C57BL , Neuropéptido Y/análisis , Neuropéptido Y/fisiología , Oligopéptidos/farmacología , Hormonas Peptídicas/sangre , Estreptozocina , alfa-MSH/análisis
11.
Circulation ; 101(25): 2962-7, 2000 Jun 27.
Artículo en Inglés | MEDLINE | ID: mdl-10869270

RESUMEN

BACKGROUND: Arterial remodeling after balloon angioplasty has been recognized as a major determinant of restenosis. Perturbation of collagen metabolism might be important. After balloon injury, matrix metalloproteinase (MMP) expression is upregulated. We investigated the effect of Batimastat, a nonspecific MMP inhibitor, on late lumen loss, arterial remodeling, and neointima formation after balloon dilation. METHODS AND RESULTS: In atherosclerotic iliac arteries of 12 Yucatan micropigs, balloon dilation was performed, with intravascular ultrasound and quantitative angiography used before and after balloon dilation and at 42-day follow-up. The animals were randomly divided into 2 groups, the Batimastat group (n=6) and the vehicle group (n=6). All animals were intraperitoneally injected with either Batimastat or a vehicle immediately after balloon dilation and at 2 weeks and 4 weeks after balloon dilation. Angiographic and echographic late lumen loss in the Batimastat group versus the vehicle group was 0.3+/-0.1 versus 0.8+/-0.1 mm (P=0.01) and 2.2+/-0.5 versus 4.9+/-0.7 mm(2) (P=0.004), respectively. Late media-bounded area loss was used as a measure of remodeling after balloon dilation and was 0.9+/-0.6 mm(2) in the Batimastat group compared with 3.8+/-0.8 mm(2) in the vehicle group (P=0.003, mixed model analysis P=0.01). Neointima formation was 1.3+/-0.3 mm(2) in the Batimastat group and 1.0+/-0.2 mm(2) in the vehicle group (P=0. 542). CONCLUSIONS: Metalloproteinase inhibition by Batimastat significantly reduced late lumen loss after balloon angioplasty by inhibition of constrictive arterial remodeling, whereas neointima formation was not inhibited by MMP inhibition.


Asunto(s)
Angioplastia de Balón/efectos adversos , Arteriosclerosis/etiología , Arteriosclerosis/terapia , Arteria Ilíaca/fisiopatología , Metaloendopeptidasas/antagonistas & inhibidores , Fenilalanina/análogos & derivados , Inhibidores de Proteasas/uso terapéutico , Tiofenos/uso terapéutico , Angiografía , Animales , Arteriosclerosis/diagnóstico , Arteriosclerosis/metabolismo , Arteria Ilíaca/diagnóstico por imagen , Arteria Ilíaca/patología , Inmunohistoquímica , Macrófagos/patología , Metaloendopeptidasas/metabolismo , Fenilalanina/sangre , Fenilalanina/uso terapéutico , Periodo Posoperatorio , Porcinos , Porcinos Enanos , Tiofenos/sangre , Túnica Íntima/diagnóstico por imagen , Túnica Íntima/patología , Ultrasonografía Intervencional
12.
Circulation ; 104(1): 91-6, 2001 Jul 03.
Artículo en Inglés | MEDLINE | ID: mdl-11435344

RESUMEN

BACKGROUND: Constrictive vascular remodeling (VR) is the most significant component of restenosis after balloon angioplasty (PTA). Whereas in physiological conditions VR is associated with normalization of shear stress (SS) and wall stress (WS), after PTA the role of SS and WS in VR is unknown. Furthermore, whereas matrix metalloproteinase inhibition (MMPI) has been shown to modulate VR after PTA, its effect on the SS and WS control mechanisms after PTA is unknown. METHODS AND RESULTS: PTA was performed in external iliac arteries of 12 atherosclerotic Yucatan pigs, of which 6 pigs (7 vessels) received the MMPI batimastat and 6 pigs (10 vessels) served as controls. Before and after the intervention and at 6-week follow-up, intravascular ultrasound pullback was performed, allowing 3D reconstruction of the treated segment and computational fluid dynamics to calculate the media-bounded area and SS. WS was derived from the Laplace formula. Immediately after PTA, media-bounded area, WS, and SS changed by 20%, 16%, and -49%, respectively, in both groups. VR was predicted by SS and WS. In the control group, SS and WS had been normalized at follow-up with respect to the reference segment. In contrast, for the batimastat group, the SS had been normalized, but not the WS. The latter is attributed to an increase in wall area at follow-up. CONCLUSIONS: Vascular remodeling after PTA is controlled by both SS and WS. MMPI inhibited the WS control system.


Asunto(s)
Angioplastia de Balón , Arteriosclerosis/fisiopatología , Inhibidores de la Metaloproteinasa de la Matriz , Fenilalanina/análogos & derivados , Fenilalanina/farmacología , Tiofenos/farmacología , Túnica Íntima/efectos de los fármacos , Animales , Arteriosclerosis/patología , Arteriosclerosis/terapia , Retroalimentación , Hemorreología , Arteria Ilíaca/diagnóstico por imagen , Arteria Ilíaca/efectos de los fármacos , Arteria Ilíaca/cirugía , Metaloproteinasas de la Matriz/metabolismo , Modelos Cardiovasculares , Inhibidores de Proteasas/farmacología , Análisis de Regresión , Estrés Mecánico , Porcinos Enanos , Túnica Íntima/patología , Ultrasonografía , Grado de Desobstrucción Vascular/efectos de los fármacos
13.
Neth Heart J ; 13(6): 224-232, 2005 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-25696496

RESUMEN

BACKGROUND: Restenosis after balloon angioplasty is in part due to remodelling, whereas restenosis after stenting is entirely due to neointima formation. Nonmuscle myosin heavy chain-B (NMMHC-B) is expressed by vascular smooth muscle cells and because of its overexpression in restenotic lesions after balloon angioplasty, NMMHC-B is proposed as a potential therapeutic target. Because the mechanisms underlying restenosis after balloon angioplasty or after stenting are different we hypothesised that the expression of NMMHC-B would differ in balloon-dilated versus stented arteries. METHODS: To study the localisation and time course of expression of NMMHC-B, we performed stenting or balloon dilation in peripheral arteries of 16 atherosclerotic Yucatan micropigs and used serial intravascular ultrasound (IVUS) and angiography to measure geometric dimensions following balloon angioplasty or stenting. In situ hybridisation techniques were used to detect NMMHC-B mRNA. 5'-bromo-2'-deoxyuridine (BrdU) was administered to detect proliferating cells. By counting the number of silver grains in the different layers of the artery, we could compare the amount of expression at the different time points between the groups. RESULTS: In intima and media, NMMHC-B expression increased after balloon dilation and stenting and peaked at 7 days. In stented arteries, the expression of NMMHC-B remained high for up to 42 days after injury, whereas in balloon-dilated arteries it had normalised. In the adventitia of balloon-dilated arteries, but not of stented arteries, NMMHC-B expression peaked at 7 days. NMMHC-B expression was not limited to proliferating cells. CONCLUSION: NMMHC-B is expressed near sites of active repair after arterial injury, but not limited to proliferating cells. The different pattern of NMMHC-B expression after balloon dilation compared with stenting may be related to arterial remodelling, because stented arteries that do not remodel lack this conspicuous adventitial expression at 7 days.

14.
Cardiovasc Res ; 27(11): 1933-8, 1993 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-8287399

RESUMEN

OBJECTIVE: The cardiac renin-angiotensin system is activated in experimental heart failure, but it is unknown at what stage of heart failure it becomes activated, and whether activation is related to ventricular dysfunction and dilatation. Changes in activity of cardiac, renal, and plasma angiotensin converting enzyme (ACE) were therefore examined at different stages of experimental heart failure, with simultaneous measurements of left ventricular pressure, systolic dP/dt, and inner ventricular radius. METHODS: Heart failure was induced by experimental infarction in 17 normotensive male Wistar rats; 14 rats were sham operated. Rats were killed 3, 5, or 80 d after infarction. In an isolated heart perfusion, left ventricular pressure and systolic dP/dT were measured. ACE activity was determined in samples of the left and right cardiac ventricle, kidney, and plasma. Radius of the ventricular cavity was planimetrically determined in transverse sections of the left ventricle. RESULTS: At the different stages both left ventricular pressure and systolic dP/dT progressively decreased and inner radius of the left ventricle increased in all heart failure groups. ACE activity in the left ventricle increased significantly in all heart failure groups and correlated inversely with left ventricular pressure (R = -0.81; p < 0.001) and dP/dt (R = -0.85; p < 0.001). ACE activity in the kidney was only increased 80 d after the induction of heart failure [17(SEM 1) v 11.2(0.5) nM His-Leu generated per min.mg-1, p < 0.01], while plasma ACE activity was not increased in any heart failure group. CONCLUSIONS: Cardiac ACE is activated in the early stage after induction of heart failure and is related to the amount of dysfunction. ACE in the kidney is activated only in the chronic stage. The cardiac renin-angiotensin system therefore already appears to be an important neurohumoral adjustment in the early stage of heart failure and is thereby a suitable target for early intervention by ACE inhibitors.


Asunto(s)
Insuficiencia Cardíaca/fisiopatología , Corazón/fisiopatología , Sistema Renina-Angiotensina/fisiología , Enfermedad Aguda , Animales , Insuficiencia Cardíaca/sangre , Insuficiencia Cardíaca/enzimología , Insuficiencia Cardíaca/patología , Frecuencia Cardíaca/efectos de los fármacos , Isoproterenol/farmacología , Riñón/enzimología , Masculino , Miocardio/enzimología , Miocardio/patología , Peptidil-Dipeptidasa A/sangre , Peptidil-Dipeptidasa A/metabolismo , Ratas , Ratas Wistar , Factores de Tiempo
15.
Cardiovasc Res ; 27(12): 2118-24, 1993 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-8313417

RESUMEN

OBJECTIVES: The purpose was to relate endothelium dependent relaxation to neurohumoral and haemodynamic changes in rats with chronic heart failure. METHODS: Rats were submitted to either coronary ligation causing myocardial infarction or banding of the abdominal aorta (aortic stenosis), and comparisons were made with normal rats (n = 20 per group). Starting six weeks after surgery, half of the experimental animals received ibopamine and the other half served as controls and were given saline for another three weeks. After this, haemodynamic and neurohumoral variables were determined and the rats were killed. Rings of both the thoracic and abdominal aorta were studied in organ baths to measure their response to vasoactive agents. RESULTS: Increased plasma noradrenaline concentrations in rats with myocardial infarction and aortic stenosis were reduced by ibopamine. Blood pressure and heart rate, which were higher in rats with aortic stenosis than in rats with myocardial infarction and in normal rats, were unaffected by ibopamine. The maximal relaxation to sodium nitrite was depressed in the thoracic aorta from rats with myocardial infarction. The pIC50 of metacholine induced relaxation was smaller in the thoracic aorta from rats with myocardial infarction and aortic stenosis. By contrast, both pIC50 and the maximal relaxation (Emax) were increased in the abdominal aorta from rats with aortic stenosis, whereas Emax was smaller in rats with myocardial infarction. Ibopamine had no significant effects on these responses. CONCLUSIONS: Endothelium dependent relaxation to metacholine was selectively altered in rats with chronic heart failure due to aortic stenosis, probably because of differences in regional haemodynamics. In rats with myocardial infarction, however, endothelium dependent relaxation was impaired in both the thoracic and abdominal aorta. Ibopamine acted as a neurohumoral modulator by reducing increased noradrenaline concentrations but had no significant effect on either endothelium dependent or independent relaxation.


Asunto(s)
Desoxiepinefrina/análogos & derivados , Endotelio Vascular/efectos de los fármacos , Insuficiencia Cardíaca/tratamiento farmacológico , Vasodilatadores/farmacología , Animales , Estenosis de la Válvula Aórtica/tratamiento farmacológico , Técnicas de Cultivo , Desoxiepinefrina/farmacología , Modelos Animales de Enfermedad , Epinefrina/sangre , Insuficiencia Cardíaca/sangre , Masculino , Cloruro de Metacolina/farmacología , Infarto del Miocardio/tratamiento farmacológico , Norepinefrina/sangre , Fenilefrina/farmacología , Ratas , Ratas Wistar
16.
Cardiovasc Res ; 39(1): 224-32, 1998 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-9764202

RESUMEN

OBJECTIVE: Remodeling in de novo atherosclerosis and in restenosis after balloon angioplasty constitutes a change in total arterial circumference which, together with plaque growth or neointimal formation, determines the lumen of the artery. To better understand the fundamental biology of neointimal formation, remodeling and their interaction, animal studies are needed. In this study, we described in detail the methodology used and the natural history of neointimal formation and remodeling after balloon angioplasty in atherosclerotic Yucatan micropigs. METHODS AND RESULTS: Atherosclerosis was induced in 60 peripheral arteries of sixteen Yucatan micropigs by a combination of denudation and atherogenic diet. Balloon angioplasty was performed in 38 arteries, with serial intravascular ultrasound (IVUS) and quantitative angiography before and after intervention and at 2, 4, 7, 14 or 42 days follow-up. Remodeling, expressed as late media-bounded area (MBA) loss, increased progressively over time. At 42 days, late MBA loss after balloon angioplasty was significantly different compared to late MBA loss in control arteries, 2.2 +/- 1.0 versus -0.3 +/- 1.1 mm2 and p = 0.02. Late lumen loss increased over time and was highest at 42 days after balloon angioplasty (2.8 +/- 0.7 mm2). The contribution of neointimal formation to late lumen loss decreased over time and the contribution of late MBA loss to late lumen increased over time and was highest at 42 days (78%). Medial necrosis was 48% at two days after balloon angioplasty and the repopulation of the media was almost completed at seven days. CONCLUSION: Remodeling following balloon angioplasty has an early onset and progresses with neointimal formation to cause restenosis over the standard 42-day time course for Yucatan micropigs. This correlates to six months renarrowing in humans. In this model, atherosclerosis and the natural history of restenosis, both with respect to neointimal formation and remodeling, resemble the human disease quite closely.


Asunto(s)
Angioplastia de Balón/efectos adversos , Enfermedad Coronaria/etiología , Modelos Animales de Enfermedad , Porcinos Enanos , Análisis de Varianza , Animales , Arteriosclerosis/diagnóstico por imagen , Arteriosclerosis/patología , Enfermedad Coronaria/diagnóstico por imagen , Enfermedad Coronaria/patología , Dieta Aterogénica , Arteria Ilíaca/diagnóstico por imagen , Radiografía , Recurrencia , Porcinos , Factores de Tiempo , Ultrasonografía Intervencional
17.
Burns ; 22(1): 15-21, 1996 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-8719310

RESUMEN

Bacteria and endotoxins can pass through the gut barrier under certain conditions. This process of bacterial translocation (BT) may occur after thermal injury in animals and is thought to play a role in the pathogenesis of septic complications in severely burned patients. The current study was performed to determine the role of endotoxin-related cytokines in the pathogenesis of burn-induced BT. Wistar rats were used in which enhanced sensitivity to TNF/LPS reactions was achieved by treatment with galactosamine (GalN). The GI tracts of these rats were antibiotic decontaminated with oral bacitracin and neomycin and were colonized with a neomycin resistant (NR)-Escherichia coli strain. The rats were divided into four groups, 30 per cent TBSA scald with GalN (Burn+GalN) pretreatment; 30 per cent TBSA scald without GalN (Burn); or sham injury with (GalN) and without GalN (Sham) pretreatment. On day 2, the animals were killed and liver, spleen, lung, heart and the peritoneal cavity were cultured. Blood samples were taken and the concentrations of LPS, TNF, IL-6 and ALAT were determined. Mortality was significantly increased in the Burn+GalN group compared to the other groups. In all groups, the incidences of BT were increased compared to the sham-treated group, although BT was most pronounced in the Burn+GalN group. In the latter group it was accompanied by highly elevated IL-6 and ALAT levels. The results of this study suggest that endotoxin mediators like TNF and IL-6 could play a role in the phenomenon of BT and that the function of the liver is an important clearing mechanism.


Asunto(s)
Traslocación Bacteriana , Quemaduras/microbiología , Escherichia coli/fisiología , Galactosamina/farmacología , Alanina Transaminasa/sangre , Animales , Antibacterianos/farmacología , Antiinfecciosos Locales/farmacología , Bacitracina/farmacología , Quemaduras/sangre , Quemaduras/tratamiento farmacológico , Recuento de Colonia Microbiana , Citocinas/sangre , Modelos Animales de Enfermedad , Escherichia coli/efectos de los fármacos , Galactosamina/administración & dosificación , Lipopolisacáridos/sangre , Masculino , Neomicina/farmacología , Ratas , Ratas Wistar , Organismos Libres de Patógenos Específicos , Distribución Tisular , Infección de Heridas/microbiología
18.
J Anim Sci ; 74(5): 1047-55, 1996 May.
Artículo en Inglés | MEDLINE | ID: mdl-8726736

RESUMEN

During two consecutive lactations using a switch-back design, 16 sows received a corn, cassava, barley, and soybean meal diet supplemented with either 8.5 or 1 g/kg of NaCl (.4% Na or .1% Na, respectively). The average daily water consumption during the 4-wk lactation period was greater (P < .01) for the sows fed the high-salt diet than for those fed the low-salt diet (13.9 vs 12.4 L, respectively). Urine production accounted for 27% of the water intake during lactation. This resulted in a difference during the entire lactation period of 42.2 L in water consumption (P = .07) and 11.4 L in urine production (P = .07). The Na and Cl concentrations of the urine for sows fed the high-salt diet were higher than for sows fed the low-salt diet (P < .05), but the K, Mg, P, and Ca concentrations were not influenced. The milk composition, measured at d 1, 13, and 27 of lactation, was relatively independent of the dietary salt level, except for the Cl concentration at d 1 after farrowing, which was higher (P < .05) for sows fed the high-salt diet. The moisture and ash content of the milk increased with the length of the lactation, irrespective of the diet. The increased ash content on d 13 and 27 of lactation was accounted for by the increased concentrations of P and Ca. There was no effect of dietary salt level on weight change of the sow or on the growth performance of the pigs. The interval from weaning to estrus (n = 13, t = 2.48, P = .029) was shorter for sows fed the high-salt diet than for sows fed the low-salt diet (6.2 +/- 1.0 and 12.6 +/- 3.1 d, respectively). More sows were unsuccessfully mated after receiving the low-salt diet during lactation. These results indicate that a low-salt diet for lactating sows results in lower water consumption, lower urine production, and lower Na and Cl concentrations in the urine. Milk composition, weight change of the sow, and growth performance of the pigs were not altered, but reproductive failures afterward may point to a salt deficiency during lactation.


Asunto(s)
Ingestión de Líquidos/efectos de los fármacos , Fertilidad/fisiología , Lactancia/fisiología , Reproducción/fisiología , Sodio en la Dieta/farmacología , Porcinos/fisiología , Animales , Calcio/análisis , Cloruros/análisis , Cloruros/orina , Relación Dosis-Respuesta a Droga , Femenino , Alimentos Fortificados , Hordeum/normas , Magnesio/análisis , Leche/química , Fósforo/orina , Distribución Aleatoria , Sodio/análisis , Sodio/orina , Sodio en la Dieta/administración & dosificación , Glycine max/normas , Porcinos/metabolismo , Aumento de Peso/fisiología , Zea mays/normas
19.
Neurogastroenterol Motil ; 25(9): e599-608, 2013 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-23781841

RESUMEN

BACKGROUND: Ghrelin is the only known peripherally active orexigenic hormone produced by the stomach that activates vagal afferents to stimulate food intake and to accelerate gastric emptying. Vagal sensory neurons within the nodose ganglia are surrounded by glial cells, which are able to receive and transmit chemical signals. We aimed to investigate whether ghrelin activates or influences the interaction between both types of cells. The effect of ghrelin was compared with that of leptin and cholecystokinin (CCK). METHODS: Cultures of rat nodose ganglia were characterized by immunohistochemistry and the functional effects of peptides, neurotransmitters, and pharmacological blockers were measured by Ca(2+) imaging using Fluo-4-AM as an indicator. KEY RESULTS: Neurons responded to KCl and were immunoreactive for PGP-9.5 whereas glial cells responded to lysophosphatidic acid and had the typical SOX-10-positive nuclear staining. Neurons were only responsive to CCK (31 ± 5%) whereas glial cells responded equally to the applied stimuli: ghrelin (27 ± 2%), leptin (21 ± 2%), and CCK (30 ± 2%). In contrast, neurons stained more intensively for the ghrelin receptor than glial cells. ATP induced [Ca(2+) ]i rises in 90% of the neurons whereas ACh and the NO donor, SIN-1, mainly induced [Ca(2+) ]i changes in glial cells (41 and 51%, respectively). The percentage of ghrelin-responsive glial cells was not affected by pretreatment with suramin, atropine, hexamethonium or 1400 W, but was reduced by l-NAME and by tetrodotoxin. Neurons were shown to be immunoreactive for neuronal NO-synthase (nNOS). CONCLUSIONS & INFERENCES: Our data show that ghrelin induces Ca(2+) signaling in glial cells of the nodose ganglion via the release of NO originating from the neurons.


Asunto(s)
Señalización del Calcio/fisiología , Ghrelina/metabolismo , Neuroglía/metabolismo , Neuronas/metabolismo , Comunicación Paracrina/fisiología , Animales , Señalización del Calcio/efectos de los fármacos , Células Cultivadas , Técnica del Anticuerpo Fluorescente , Ghrelina/farmacología , Inmunohistoquímica , Neuroglía/efectos de los fármacos , Neuronas/efectos de los fármacos , Ganglio Nudoso , Comunicación Paracrina/efectos de los fármacos , Ratas , Ratas Wistar
20.
Clin Microbiol Infect ; 19(9): 832-7, 2013 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-23173820

RESUMEN

The Burkholderia cepacia complex is a group of Gram-negative bacteria known as respiratory pathogens in cystic fibrosis patients, but also increasingly reported as a cause of healthcare associated infections. We describe an outbreak of B. cepacia bloodstream infections in a referral hospital in Phnom Penh, Cambodia. Over a 1.5-month period, blood cultures from eight adult patients grew B. cepacia. Bloodstream infection occurred after a median of 2.5 days of hospitalisation. Three patients died: 7, 10 and 17 days after blood cultures were sampled. As part of the outbreak investigation, patient files were reviewed and environmental sampling was performed. All patients had peripheral venous catheters that were flushed with Ringer lactate drawn from a 1 L bag, used as multiple-dose vial at the ward. Cultures of unopened Ringer lactate and disinfectants remained sterile but an in-use bag of Ringer lactate solution and the dispensing pin grew B. cepacia. The isolates from patients and flushing solution were identified as B. cepacia by recA gene sequence analysis, and random amplified polymorphic DNA typing confirmed clonal relatedness. The onset of the outbreak had coincided with the introduction of a dispensing pin with a screw fit that did not allow proper disinfection. Re-enforcement of aseptic procedures with sterile syringe and needle has ended the outbreak. Growth of B. cepacia should alert the possibility of healthcare associated infection also in tropical resource-limited settings. The use of multiple-dose vials should be avoided and newly introduced procedures should be assessed for infection control risks.


Asunto(s)
Bacteriemia/epidemiología , Infecciones por Burkholderia/epidemiología , Burkholderia cepacia/aislamiento & purificación , Infecciones Relacionadas con Catéteres/epidemiología , Infección Hospitalaria/epidemiología , Contaminación de Medicamentos , Soluciones Isotónicas , Adulto , Anciano , Bacteriemia/microbiología , Técnicas de Tipificación Bacteriana , Infecciones por Burkholderia/microbiología , Infecciones por Burkholderia/prevención & control , Burkholderia cepacia/genética , Cambodia/epidemiología , Infecciones Relacionadas con Catéteres/microbiología , Infección Hospitalaria/prevención & control , Brotes de Enfermedades , Femenino , Humanos , Control de Infecciones/métodos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Técnica del ADN Polimorfo Amplificado Aleatorio , Lactato de Ringer , Dispositivos de Acceso Vascular
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA