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1.
Public Health ; 196: 117-123, 2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-34182257

RESUMEN

OBJECTIVES: Persons experiencing homelessness (PEH) are known to be often excluded from primary health care and community prevention programmes leading to high use of hospital emergency departments (EDs). This study aimed to identify demographic features, clinical characteristics and attendance outcomes of PEH presenting to ED. STUDY DESIGN: Analysis of routinely collected data set. METHODS: Clinical presentations and drug prescription data of PEH who presented a major ED in the West Midlands region of England from 2014 to 2019 were extracted and analysed using descriptive and inferential statistics. RESULTS: During the study period, 3271 of 596,198 presentations were made by PEH; 74% PEH attendees were male. Drug- and alcohol-related conditions, as well as pain and injury constituted the most frequent reasons for presentation, contributing to over half of all presentations. A significantly higher proportion of males (n = 481, 20.3%) presented with drug and alcohol problems than females (n = 93, 11.2%) (P ≤ 0.001). However, pain was the primary reason for presentation for twice as many female patients (n = 189, 22.8%) compared with males (n = 305, 12.9%) (P < 0.001). Nearly one in five left the ED before being assessed and a total of 39 patients (1.2%) died in the ED and 785 (24.0%) required in-patient admissions to the same hospital. CONCLUSIONS: Drug, alcohol and pain including the need of opioid analgesics constituted the majority of presentations made by PEH in ED. The observed rate of death of PEH in ED is 12 times higher than the general population. A very high proportion of PEH also leave the ED before being treated. Future research should focus on strengthening community interventions, particularly to improve access to those at risk of dual diagnoses of substance misuse and mental health problems. Interventions involving multisector collaborations are needed to improve seamless discharge from ED and minimise repeat attendance. Gender differences in the nature of presentations and ED outcomes needs to be investigated further.


Asunto(s)
Servicio de Urgencia en Hospital , Personas con Mala Vivienda , Femenino , Humanos , Masculino , Admisión del Paciente , Grupos de Población , Atención Primaria de Salud
2.
Dis Esophagus ; 30(4): 1-8, 2017 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-28375478

RESUMEN

Intraoperative pyloric procedures are often performed during esophagectomies to reduce the rates of gastric conduit dysfunction. They include pyloroplasty (PP), pyloromyotomy (PM), and pylorus botulinum toxin type-A injections (BI). Despite these procedures, patients frequently warrant further endoscopic interventions. The aim of this study is to compare intraoperative pyloric procedures and the rates of postoperative endoscopic interventions following minimally invasive esophagectomy (MIE). We identified patients who underwent MIE for esophageal carcinoma and grouped them as 'None' (no intervention), 'PP', 'PM', or 'BI' based on intraoperative pyloric procedure type. The rates of endoscopic interventions for the first six postoperative months were compared. To adjust for variability due to MIE type, the rates of >1 interventions were compared using a zero-inflated Poisson regression analysis. Significance was established at P < 0.05. There were 146 patients who underwent an MIE for esophageal cancer from 2008 to 2015; 77.4% were three-hole MIE, and 22.6% were Ivor- Lewis MIE. BI was most frequent in Ivor-Lewis patients (63.5%), while PP was most frequent (46.9%) in three-hole patients. Postoperative endoscopic interventions occurred in 38 patients (26.0%). The BI group had the highest percentage of patients requiring a postoperative intervention (n = 13, 31.7%). After adjusting for higher rates of interventions in three-hole MIE patients, the BI and None groups had the lowest rates of >1 postoperative interventions. Our data did not show superiority of any pyloric intervention in preventing endoscopic interventions. The patients who received BI to the pylorus demonstrated a trend toward a greater likelihood of having a postoperative intervention. However when adjusted for type of MIE, the BI and None groups had lower rates of subsequent multiple interventions. Further research is needed to determine if the choice of intraoperative pyloric procedure type significantly affects quality of life, morbidity, and overall prognosis in these patients.


Asunto(s)
Endoscopía Gastrointestinal/métodos , Esofagectomía/métodos , Cuidados Intraoperatorios/métodos , Cuidados Posoperatorios/métodos , Píloro/cirugía , Adulto , Anciano , Anciano de 80 o más Años , Esofagectomía/efectos adversos , Femenino , Vaciamiento Gástrico , Humanos , Cuidados Intraoperatorios/efectos adversos , Masculino , Persona de Mediana Edad , Distribución de Poisson , Complicaciones Posoperatorias/etiología , Complicaciones Posoperatorias/prevención & control , Complicaciones Posoperatorias/cirugía , Periodo Posoperatorio , Análisis de Regresión , Estudios Retrospectivos , Gastropatías/etiología , Gastropatías/prevención & control , Gastropatías/cirugía , Resultado del Tratamiento
3.
Behav Res Methods ; 48(2): 614-20, 2016 06.
Artículo en Inglés | MEDLINE | ID: mdl-26092392

RESUMEN

We have constructed and tested a custom-made magnetic-imaging-compatible visual projection system designed to project on a very wide visual field (~80°). A standard projector was modified with a coupling lens, projecting images into the termination of an image fiber. The other termination of the fiber was placed in the 3-T scanner room with a projection lens, which projected the images relayed by the fiber onto a screen over the head coil, viewed by a participant wearing magnifying goggles. To validate the system, wide-field stimuli were presented in order to identify retinotopic visual areas. The results showed that this low-cost and versatile optical system may be a valuable tool to map visual areas in the brain that process peripheral receptive fields.


Asunto(s)
Imagen por Resonancia Magnética/instrumentación , Imagen por Resonancia Magnética/métodos , Estimulación Luminosa/instrumentación , Estimulación Luminosa/métodos , Adulto , Mapeo Encefálico , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador , Imagen por Resonancia Magnética/economía , Masculino , Persona de Mediana Edad , Reproducibilidad de los Resultados , Campos Visuales
4.
Int J Immunopathol Pharmacol ; 26(3): 621-32, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-24067459

RESUMEN

Osteosarcoma is the most common primary malignant tumour of the bone. Although new therapies continue to be reported, osteosarcoma-related morbidity and mortality remain high. Modern medicine has greatly increased knowledge of the physiopathology of this neoplasm. Novel targets for drug development may be identified through an understanding of the normal molecular processes that are deeply modified in pathological conditions. The aim of the present study is to investigate, by immunohistochemistry, the localisation of different growth factors and of the proliferative marker Ki-67 in order to determine whether these factors are involved in the transformation of osteogenic cells and in the development of human osteosarcoma. We observed a general positivity for NGF - TrKA - NT3 - TrKC - VEGF in the cytoplasm of neoplastic cells and a strong expression for NT4 in the nuclear compartment. TGF-beta was strongly expressed in the extracellular matrix and vascular endothelium. BDNF and TrKB showed a strong immunolabeling in the extracellular matrix. Ki-67/MIB-1 was moderately expressed in the nucleus of neoplastic cells. We believe that these growth factors may be considered potential therapeutic targets in the treatment of osteosarcoma, although proof of this hypothesis requires further investigation.


Asunto(s)
Neoplasias Óseas/metabolismo , Proliferación Celular , Células Endoteliales/metabolismo , Péptidos y Proteínas de Señalización Intercelular/metabolismo , Osteosarcoma/metabolismo , Receptores de Factores de Crecimiento/metabolismo , Antineoplásicos/uso terapéutico , Neoplasias Óseas/irrigación sanguínea , Neoplasias Óseas/tratamiento farmacológico , Neoplasias Óseas/patología , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Diseño de Fármacos , Células Endoteliales/efectos de los fármacos , Células Endoteliales/patología , Técnica del Anticuerpo Fluorescente , Humanos , Inmunohistoquímica , Antígeno Ki-67/metabolismo , Terapia Molecular Dirigida , Osteosarcoma/irrigación sanguínea , Osteosarcoma/tratamiento farmacológico , Osteosarcoma/patología , Receptores de Factores de Crecimiento/efectos de los fármacos , Transducción de Señal
5.
Clin Toxicol (Phila) ; 60(10): 1094-1098, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-35943421

RESUMEN

OBJECTIVE: Synthetic cannabinoid receptor agonists (SCRA) are commonly encountered new psychoactive substances. Here we report the recent detection of ADB-BUTINACA in samples from patients attending United Kingdom emergency departments with toxicity after suspected drug misuse and describe the associated clinical features. METHODS: Consenting adults (≥16 y) presenting to participating hospitals with toxicity after suspected drug misuse have been included in the Identification Of Novel psychoActive substances (IONA) study since March 2015. Demographic and clinical features are recorded and blood and/or urine samples analysed using high-resolution accurate mass liquid chromatography-mass spectrometry. RESULTS: By December 2021, analytical data were available for 1279 IONA participants and ADB-BUTINACA was detected in at least one sample from 10 (9 males, age range 16-51 median 45 years), all presenting since February 2021. Smoking 'spice' was reported by four patients, two had ingested edible "cannabis" gums and four reported heroin use (2 intravenous, 1 smoked, 1 route not known). Co-use of pregabalin (oral) and crack cocaine (smoked) were also reported. In 3 cases ADB-BUTINACA was the only substance detected, while in seven other substances of misuse were also detected including other SCRA, opioids, benzodiazepines cocaine and pregabalin. Clinical features reported in these 2 groups respectively included reduced level of consciousness (3/3, 6/7), agitation (0/3, 4/7), tachycardia (0/3, 3/7), seizures (1/3, 1/7), hallucinations (1/3, 1/7), hypotension (1/3, 1/7). Metabolic acidosis (1/3, 0/7) and respiratory acidosis (1/3, 0/7), All 10 patients recovered with supportive care, including intubation and ventilation for one case. The median length of hospital stay was 19 h (range 2.6-131 h). CONCLUSIONS: ADB-BUTINACA has recently emerged as a drug of misuse in England. Clinical features of toxicity are consistent with those of other SCRA and include reduced level of consciousness, respiratory and/or metabolic acidosis, seizures, confusion and hallucinations.


Asunto(s)
Agonistas de Receptores de Cannabinoides , Cocaína Crack , Adulto , Masculino , Humanos , Adolescente , Adulto Joven , Persona de Mediana Edad , Heroína , Pregabalina , Servicio de Urgencia en Hospital , Inglaterra/epidemiología , Alucinaciones , Benzodiazepinas , Convulsiones
6.
Food Chem Toxicol ; 158: 112608, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34656697

RESUMEN

Methylglyoxal (MG), a potent glycotoxin that can be found in the diet, is one of the main precursors of Advanced glycation end products (AGEs). It is well known that modifications in lifestyle such as nutritional interventions can be of great value for preventing brain deterioration. This study aimed to evaluate in vivo how an oral MG treatment, that mimics a high MG dietary intake, could affect brain health. From our results, we demonstrated that MG administration affected working memory, and induced neuroinflammation and oxidative stress by modulating the Receptor for Advanced glycation end products (RAGE). The gene and protein expressions of RAGE were increased in the hippocampus of MG mice, an area where the activity of glyoxalase 1, one of the main enzymes involved in MG detoxification, was found reduced. Furthermore, at hippocampus level, MG mice showed increased expression of proinflammatory cytokines and increased activities of NADPH oxidase and catalase. MG administration also increased the gene and protein expressions of Presenilin-1, a subunit of the gamma-secretase protein complex linked to Alzheimer's disease. These findings suggest that high MG oral intake induces alteration directly in the brain and might establish an environment predisposing to AD-like pathological conditions.


Asunto(s)
Encéfalo/efectos de los fármacos , Cognición/efectos de los fármacos , Dieta , Productos Finales de Glicación Avanzada/toxicidad , Presenilina-1/metabolismo , Piruvaldehído/toxicidad , Receptor para Productos Finales de Glicación Avanzada/metabolismo , Envejecimiento , Enfermedad de Alzheimer/etiología , Enfermedad de Alzheimer/metabolismo , Enfermedad de Alzheimer/patología , Animales , Encéfalo/metabolismo , Catalasa/metabolismo , Citocinas/metabolismo , Femenino , Hipocampo/efectos de los fármacos , Hipocampo/metabolismo , Inflamación/etiología , Inflamación/metabolismo , Lactoilglutatión Liasa/metabolismo , Masculino , Memoria/efectos de los fármacos , Ratones , NADPH Oxidasas/metabolismo , Enfermedades Neuroinflamatorias/etiología , Enfermedades Neuroinflamatorias/metabolismo , Enfermedades Neuroinflamatorias/patología , Estrés Oxidativo
7.
J Neurosci Methods ; 341: 108720, 2020 07 15.
Artículo en Inglés | MEDLINE | ID: mdl-32416472

RESUMEN

BACKGROUND: DNA methylation plays a relevant role in the regulation of gene transcription, but currently the exact quantification of transcription factors binding to methylated DNA is not being determined. The binding of the transcription factor cAMP response element-binding protein-1 to its cognate CpG containing motif is known to be impaired upon methylation. It thus represents a paradigmatic system to experimentally verify the validity of a new in vitro method to measure the role of methylation on DNA/transcription factors binding. METHOD: An AlphaScreen® assay was developed to quantitatively measure the contribution of DNA CpG methylation on the interaction with transcription factors. The method was validated measuring the variation in affinity of cAMP response element-binding protein-1 and its recognition motif in human Brain-derived neurotrophic factor gene exon IV promoter as a function of CpG methylation. RESULTS: For the first time, a quantitative direct correlation between DNA methylation and transcription factors binding is reported showing a dramatic reduction in binding affinity between fully methylated and non-methylated DNA. COMPARISON WITH EXISTING METHODS: This methodology allows to directly measure DNA/transcription factors binding ability as a function of DNA methylation levels thus improving not quantitative methods available today. Moreover, it allows to work with purified proteins and oligonucleotides without need of chromatin. CONCLUSIONS: The present methodology is suggested as a new analytical tool for the quantitative determination of the effect of CpG methylation on the interaction of gene promoters with transcription factors regulating gene expression, a key epigenetic mechanism implicated in many physiological and pathological conditions.


Asunto(s)
Metilación de ADN , Epigénesis Genética , Inmunoprecipitación de Cromatina , Proteína de Unión a Elemento de Respuesta al AMP Cíclico/genética , Humanos , Regiones Promotoras Genéticas , Unión Proteica
8.
Water Res ; 42(3): 643-52, 2008 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-17904611

RESUMEN

This study investigated the sorption of paraquat and 2,4-D on polymerin, the humic acid-like fraction of olive mill wastewater. Effects of pH, contact time, initial concentration and sorbent dosage on the sorption of both herbicides were studied. The sorption mechanism of paraquat on polymerin was consistent with the ion exchange of this herbicide with Ca, Mg and K natively occurring in the sorbent; in contrast, 2,4-D was bound to polymerin by hydrogen bonding. Simulated wastewaters contaminated with paraquat were purified after three sorption cycles on polymerin renewed at each cycle, at a solid/liquid ratio of 0.5, whereas those containing 2,4-D showed a maximal residue removal of 44% after two sorption cycles at the same ratio. The possible application of this model to other water-soluble herbicides, as well as the possible exploitation of polymerin as a bio-filter for the decontamination of pollution point sources is briefly discussed.


Asunto(s)
Ácido 2,4-Diclorofenoxiacético/química , Herbicidas/química , Residuos Industriales , Olea , Paraquat/química , Polímeros/química , Contaminantes Químicos del Agua/química , Adsorción , Industria de Procesamiento de Alimentos , Eliminación de Residuos Líquidos/métodos , Purificación del Agua/métodos
9.
J Hum Hypertens ; 31(4): 253-257, 2017 04.
Artículo en Inglés | MEDLINE | ID: mdl-27629242

RESUMEN

Poor adherence with pharmacotherapy is well recognised as one of the main barriers to achieving satisfactory blood pressure control, although accurately measuring patient adherence has historically been very challenging. Urine analysis by high-performance liquid chromatography-tandem mass spectrometry has recently become routinely available as a method of screening for non-adherence. In addition to measuring rates of adherence in hypertensive patients, this study aimed to investigate the reasons for non-adherence given by patients and how patients react when they are informed of their results. This was a retrospective observational study looking at results from the routine use of this assay in a specialist hypertension clinic in Birmingham, UK, in patients with uncontrolled hypertension and those under consideration for renal denervation. Out of the 131 patients analysed, only 67 (51%) were taking all their medications as prescribed. Forty-three patients (33%) were taking some of their medications, whilst 21 patients (16%) were completely non-adherent. The most common reasons cited for non-adherence were adverse effects of medication and forgetfulness. Adherence rates for thiazide/thiazide-like diuretics and spironolactone were lower than for other classes of antihypertensive drug. Despite the objective nature and high sensitivity of the test, 36% of non-adherent patients disputed the results. A minority of patients did not attend follow-up. Further research investigating the implications of a 'non-adherence' result on the patient-clinician relationship is required.


Asunto(s)
Antihipertensivos/orina , Hipertensión/tratamiento farmacológico , Cumplimiento de la Medicación/estadística & datos numéricos , Antihipertensivos/uso terapéutico , Humanos , Cumplimiento de la Medicación/psicología , Estudios Retrospectivos
11.
Cancer Res ; 55(1): 90-5, 1995 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-7805047

RESUMEN

The receptors for urokinase plasminogen activator were studied in both normal human fibroblasts (WI-38 cells) and their SV40-transformed counterpart (VA-13 cells). We have shown that transformed cells expose 10 times more urokinase plasminogen activator receptors (u-PAR) than normal cells. By cross-linking aliquots of cell lysates with the aminoterminal fragment of the A chain of u-PA, containing the receptor-binding sequence, we have observed a u-PAR concentration at focal contacts in both cell lines. Only transformed cells were able to efficiently invade the basement membrane Matrigel. Switching off the receptor gene expression by the anti-messenger oligodeoxynucleotides strategy abolished the invasive properties of transformed cells. The anti-messenger oligodeoxynucleotide sequence we have designed inhibited the u-PAR gene expression, lowering both the receptor and the receptor mRNA. This indicates that overexpression of u-PAR gene is itself responsible for invasivity of transformed fibroblasts in our cell model system and that antisense compound therapy may prove to be of clinical interest in the control of cancer spreading.


Asunto(s)
Invasividad Neoplásica , Oligonucleótidos Antisentido/farmacología , Receptores de Superficie Celular/metabolismo , Secuencia de Bases , Transformación Celular Viral , Células Cultivadas , Fibroblastos , Humanos , Datos de Secuencia Molecular , Activadores Plasminogénicos/metabolismo , Receptores del Activador de Plasminógeno Tipo Uroquinasa , Virus 40 de los Simios , Activador de Plasminógeno de Tipo Uroquinasa/metabolismo
12.
J Neuroimmunol ; 294: 32-40, 2016 05 15.
Artículo en Inglés | MEDLINE | ID: mdl-27138096

RESUMEN

The development of multiple sclerosis, a major neurodegenerative disease, is due to both genetic and environmental factors that might trigger aberrant epigenetic changes of the genome. In this study, we analysed global DNA methylation in the brain of mice upon induction of experimental autoimmune encephalomyelitis (EAE), and the effect of environmental enrichment (EE). We demonstrate that global DNA methylation decreased in the striatum, but not in the cortex, of EAE mice compared to healthy controls, in particular in neuronal nitric oxide synthase (nNOS)-positive interneurons of this brain area. Also, in the striatum but again not in the cortex, decreased DNA methylation of the nNOS downstream effector, dexamethasone-induced Ras protein 1 (Dexras 1), was observed in EAE mice, and was paralleled by an increase in its mRNA. Interestingly, EE was able to revert EAE effects on mRNA expression and DNA methylation levels of Dexras 1 and reduced gene expression of nNOS and 5-lipoxygenase (Alox5). Conversely, interleukin-1ß (IL-1ß) gene expression was found up-regulated in EAE mice compared to controls and was not affected by EE. Taken together, these data demonstrate an unprecedented epigenetic modulation of nNOS-signaling in the pathogenesis of multiple sclerosis, and show that EE can specifically revert EAE effects on Dexras 1 along this pathway.


Asunto(s)
Encéfalo/metabolismo , Encefalomielitis Autoinmune Experimental/patología , Epigénesis Genética/fisiología , Óxido Nítrico Sintasa de Tipo I/metabolismo , Transducción de Señal/fisiología , Proteínas ras/metabolismo , 5-Metilcitosina/metabolismo , Animales , Antiinflamatorios/farmacología , Araquidonato 5-Lipooxigenasa/metabolismo , Encéfalo/efectos de los fármacos , Encéfalo/patología , Citocinas/genética , Citocinas/metabolismo , Dexametasona/farmacología , Modelos Animales de Enfermedad , Fosfoproteína 32 Regulada por Dopamina y AMPc/metabolismo , Encefalomielitis Autoinmune Experimental/inmunología , Encefalomielitis Autoinmune Experimental/metabolismo , Epigénesis Genética/efectos de los fármacos , Femenino , Ratones , Ratones Endogámicos C57BL , Glicoproteína Mielina-Oligodendrócito/inmunología , Neuronas/metabolismo , Fragmentos de Péptidos/inmunología , Transducción de Señal/efectos de los fármacos , Proteínas ras/genética
13.
Biochim Biophys Acta ; 885(3): 301-8, 1986 Mar 14.
Artículo en Inglés | MEDLINE | ID: mdl-3004604

RESUMEN

We have found the existence of specific receptors for the plasminogen activator, urokinase, in A431 human epidermoid carcinoma cells, cultures in plasminogen-free conditions. Two subsets of receptors have been recognized on the basis of 125I-labelled urokinase binding analysis: about 1 X 10(3) high-affinity (Kd = 5.0 X 10(-11) M) and 1 X 10(5) low-affinity (Kd = 9 X 10(-9) M) receptors per cell. The electron microscopic observation of a urokinase: ferritin conjugate has shown single and clustered receptors at the cell surface. Down-regulation of the receptors (T1/2 = 3.77 h) follows the binding of urokinase. The binding does not involve an intact catalytic site and is inhibited by a monoclonal antibody against the Mr 17500 proteolytic fragment of the A chain of urokinase.


Asunto(s)
Receptores de Superficie Celular/metabolismo , Activador de Plasminógeno de Tipo Uroquinasa/metabolismo , Precursor de Proteína beta-Amiloide , Anticuerpos Monoclonales , Benzamidinas/farmacología , Carcinoma de Células Escamosas , Proteínas Portadoras/farmacología , Línea Celular , Membrana Celular/metabolismo , Humanos , Microscopía Electrónica , Peso Molecular , Nexinas de Proteasas , Receptores del Activador de Plasminógeno Tipo Uroquinasa , Activador de Plasminógeno de Tipo Uroquinasa/inmunología
14.
J Invest Dermatol ; 94(3): 310-6, 1990 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-2155272

RESUMEN

On the basis of both 125I-labeled plasminogen activator binding analysis and transmission electron microscopy studies of the interaction of a plasminogen activator/gold complex with cell membranes, we have found that human keratinocytes have specific receptors for human urokinase-type plasminogen activator distributed on the cell surface as singlets, or as small or large clusters. The use in binding experiments of the purified A chain of urokinase-plasminogen activator and of anti-A chain monoclonal antibodies has indicated that cell receptors are specific for a sequence present on the A chain, as previously reported for other cells. The interaction of both the native molecule and the purified A chain with such receptors stimulates mobilization of keratinocytes in an in vitro cell model system (Boyden chamber), when present in the lower compartment of the migration apparatus in nanomolar concentrations. Preincubation of chemoattractants with a monoclonal antibody which prevents receptor/ligand interaction also prevents plasminogen activator-induced cell migration. These data suggest that, under the conditions used in this in vitro model system, the plasminogen activator-dependent mobilization of keratinocytes depends on the interaction of the ligand with free receptors on the cell surface, and is independent of plasmin generation.


Asunto(s)
Queratinocitos/fisiología , Receptores de Superficie Celular/fisiología , Activador de Plasminógeno de Tipo Uroquinasa/farmacología , Anticuerpos Monoclonales/inmunología , Movimiento Celular/efectos de los fármacos , Células Epidérmicas , Epidermis/metabolismo , Humanos , Queratinocitos/efectos de los fármacos , Queratinocitos/metabolismo , Receptores del Activador de Plasminógeno Tipo Uroquinasa , Activador de Plasminógeno de Tipo Uroquinasa/inmunología
15.
Endocrinology ; 132(2): 806-14, 1993 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-8425495

RESUMEN

Western blot analyses of the rat pituitary have detected a 22K PRL variant distinct from intact PRL (25K). We recently reported that glandular kallikrein (GK), an estrogen-induced lactotroph protease, can process PRL in vitro from a 25K form to a 22K form in a thiol-dependent cleavage at Arg174-Arg175 to remove 23 amino acids. We also detected an estrogen- and thiol-induced 22K PRL variant in the rat pituitary comigrating with a PRL product generated by in vitro processing with GK and carboxypeptidase-B. This study addressed whether the in vivo 22K PRL variant originates through a GK-like cleavage and is a regulated secretory product of the rat pituitary. A polyclonal antipeptide antiserum was raised against a synthetic peptide [PRL-(163-173)] representing the new C-terminus after GK and carboxypeptidase-B processing. In slot and Western blots, this antiserum (CT-antiserum) specifically recognized PRL processed in vitro by GK and carboxypeptidase-B and did not recognize intact PRL or PRL cleaved by GK alone. Western blot analysis of rat pituitary extracts with CT-antiserum specifically detected an estrogen- and thiol-induced 22K band that comigrated with a PRL product generated by in vitro processing with GK and carboxypeptidase-B. This 22K band was concentrated in subcellular fractions of the pituitary enriched in secretory granules. During short term incubations in medium 199, pituitaries from normal adult female rats released substantial amounts of 22K PRL; in contrast, male pituitaries did not release detectable 22K PRL. The release of 22K PRL from female pituitaries was powerfully blocked by bromocriptine, a dopaminergic agonist. GK was also released from pituitaries of female, but not male, rats, and GK release was inhibited by bromocriptine. The results identify the 22K PRL variant as PRL-(1-173), which is consistent with GK-like processing at Arg174-Arg175, followed by carboxypeptidase-B-like processing. The results also show that 22K PRL is a natural female-specific secretory product of the rat pituitary under inhibitory dopaminergic control.


Asunto(s)
Gránulos Citoplasmáticos/metabolismo , Variación Genética , Adenohipófisis/metabolismo , Prolactina/metabolismo , Secuencia de Aminoácidos , Animales , Western Blotting , Bromocriptina/farmacología , Cisteamina/farmacología , Dietilestilbestrol/farmacología , Femenino , Sueros Inmunes , Técnicas In Vitro , Calicreínas/metabolismo , Masculino , Datos de Secuencia Molecular , Peso Molecular , Oligopéptidos/síntesis química , Oligopéptidos/inmunología , Orgánulos/efectos de los fármacos , Orgánulos/metabolismo , Ovariectomía , Adenohipófisis/efectos de los fármacos , Prolactina/análisis , Prolactina/genética , Procesamiento Proteico-Postraduccional , Ratas , Calicreínas de Tejido , Tripsina/farmacología
16.
Hypertension ; 25(4 Pt 2): 752-7, 1995 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-7721428

RESUMEN

We examined the regulatory influence of nitric oxide on development of calcium- and protein kinase C-dependent basal tone in rings of thoracic aortas from rats with aortic coarctation-induced hypertension and from normotensive controls. Aortic rings from hypertensive rats but not those from normotensive rats, bathed in Krebs' bicarbonate buffer and subjected to 2 g of passive stretch, were relaxed by removal of calcium from the buffer and by the protein kinase C inhibitors staurosporine and calphostin C. Protein kinase C activity was much greater in homogenates of aortae from hypertensive rats than in those from normotensive controls (2124 +/- 785 versus 608 +/- 73 pmol.min-1.mg protein-1, respectively). Relaxant responses to removal of calcium and to staurosporine were greater in aortic rings rubbed to remove the vascular endothelium than in endothelium-intact rings (-1.07 +/- 0.12 versus -0.70 +/- 0.10 g tension/mg tissue, respectively, for calcium removal and -1.10 +/- 0.12 versus -0.65 +/- 0.08 g tension/mg tissue, respectively, for staurosporine). Treatment with an inhibitor of nitric oxide synthesis increased calcium-dependent tone in both intact and endothelium-denuded aortic rings from hypertensive rats. Conversely, the administration of sodium nitroprusside or L-arginine reversed tone in both intact and denuded aortic rings from hypertensive rats, but acetylcholine reversed tone only in intact rings. The relaxant effects of these agents were paralleled by increases in cyclic guanosine monophosphate in aortic tissue. We conclude that aortic rings from rats with aortic coarctation-induced hypertension display calcium-dependent, protein kinase C-mediated tone in the absence of exogenous vasoconstrictors.(ABSTRACT TRUNCATED AT 250 WORDS)


Asunto(s)
Aorta/fisiopatología , Calcio/fisiología , Hipertensión/fisiopatología , Proteína Quinasa C/fisiología , Sistema Vasomotor/fisiopatología , Acetilcolina/farmacología , Animales , Arginina/farmacología , GMP Cíclico/metabolismo , Técnicas In Vitro , Masculino , Nitroprusiato/farmacología , Ratas , Ratas Sprague-Dawley , Sistema Vasomotor/efectos de los fármacos
17.
Hypertension ; 27(1): 19-24, 1996 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-8591882

RESUMEN

We investigated the contribution of nitric oxide to the short-term blood pressure reduction caused by interruption of the renin-angiotensin system in angiotensin-dependent hypertension. The blood pressure of rats made hypertensive by coarctation of the aorta between the renal arteries at their origin fell after administration of the angiotensin-converting enzyme inhibitor ramiprilat (2 mg/kg IV; -75 +/- 5 mm Hg) or the angiotensin II antagonist losartan (30 mg/kg IV; -79 +/- 6 mm Hg). But the antihypertensive effect of these agents was attenuated in rats pretreated with NG-nitro-L-arginine methyl ester (10 mg/kg IV) to inhibit nitric oxide synthesis (ramiprilat, -23 +/- 7 mm Hg; losartan, -37 +/- 5 mm Hg). In rats made hypertensive by long-term infusion of angiotensin II (60 ng/min IV, 6 to 7 days), the vasodepressor response to discontinuation of the angiotensin II infusion also was attenuated by pretreatment with the nitric oxide synthesis inhibitor (-52 +/- 7 versus -31 +/- 7 mm Hg); this attenuation was not demonstrable in rats receiving sodium nitroprusside (1 microgram.kg-1.min-1 IV) to replace the loss of endogenous nitric oxide (-72 +/- 9 mm Hg). Pretreatment with NG-nitro-L-arginine methyl ester did not interfere with the vasodepressor effect of sodium nitroprusside or prazosin in rats with aortic coarctation-induced hypertension or with the blood pressure reduction caused by discontinuation of an infusion of phenylephrine in rats made hypertensive by long-term administration of this drug. These data suggest a contribution of nitric oxide to the blood pressure reduction caused by interruption of the renin-angiotensin system in models of established angiotensin-dependent hypertension.


Asunto(s)
Angiotensina II/antagonistas & inhibidores , Presión Sanguínea/efectos de los fármacos , Hipertensión/fisiopatología , Óxido Nítrico/fisiología , Angiotensina II/administración & dosificación , Angiotensina II/farmacología , Inhibidores de la Enzima Convertidora de Angiotensina/farmacología , Animales , Coartación Aórtica/complicaciones , Arginina/análogos & derivados , Arginina/farmacología , Compuestos de Bifenilo/farmacología , Hipertensión/inducido químicamente , Hipertensión/etiología , Imidazoles/farmacología , Losartán , Masculino , NG-Nitroarginina Metil Éster , Óxido Nítrico Sintasa/antagonistas & inhibidores , Ramipril/análogos & derivados , Ramipril/farmacología , Ratas , Ratas Sprague-Dawley , Renina/sangre , Tetrazoles/farmacología , Vasoconstrictores/farmacología
18.
Hypertension ; 23(6 Pt 1): 744-51, 1994 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-8206572

RESUMEN

We contrasted in normotensive and hypertensive rats the effect of inhibition of nitric oxide synthesis on isometric tension development by aortic rings bathed in Krebs' bicarbonate buffer. NG-Nitro-L-arginine methyl ester (L-NAME) (3 x 10(-4) mol/L) increased tension (82 +/- 11% of the response to 120 mmol/L potassium chloride) in rings of thoracic aorta taken from hypertensive rats 7 to 14 days after aortic coarctation, whereas rings of abdominal aorta from below the coarctation were unresponsive, as were rings of thoracic aorta from rats with deoxycorticosterone-salt-induced hypertension and from the corresponding normotensive controls of either model of hypertension. The contractile response to L-NAME in aortic rings of rats with aortic coarctation was reversed by L-arginine (1 mmol/L), attenuated by removal of the endothelium, and blunted by the protein kinase C inhibitor staurosporine but was unaffected by inhibition of cyclooxygenase, scavengers of superoxide anion, or blockade of receptors for angiotensin, norepinephrine, serotonin, or endothelin. In additional experiments we contrasted the effect of L-NAME (10 mg/kg IV) on the blood pressure of sham-operated rats and rats with aortic coarctation after pretreatment of animals in both groups with DuP 753 (30 mg/kg IV) to achieve blood pressure equalization. The pressor response to L-NAME was twofold greater in rats with aortic coarctation than in sham-operated controls. That pressor and aortic constrictor responsiveness to L-NAME are increased after aortic coarctation suggests that a mechanism of vasodilation, mediated by nitric oxide, is preferentially manifested in rats with aortic coarctation-induced hypertension.


Asunto(s)
Aorta Torácica/fisiología , Hipertensión/fisiopatología , Óxido Nítrico/antagonistas & inhibidores , Animales , Antihipertensivos/farmacología , Aorta Torácica/efectos de los fármacos , Coartación Aórtica/complicaciones , Arginina/análogos & derivados , Arginina/farmacología , Compuestos de Bifenilo/farmacología , Presión Sanguínea/efectos de los fármacos , Hipertensión/etiología , Imidazoles/farmacología , Técnicas In Vitro , Losartán , Masculino , Azul de Metileno/farmacología , NG-Nitroarginina Metil Éster , Fenilefrina/farmacología , Ratas , Ratas Sprague-Dawley , Tetrazoles/farmacología , Vasoconstricción/efectos de los fármacos
19.
Gene ; 171(1): 9-17, 1996 May 24.
Artículo en Inglés | MEDLINE | ID: mdl-8675038

RESUMEN

A striking feature of recent outbreaks of vancomycin-resistant (VmR) enterococci is the apparent horizontal dissemination of resistance determinants. The plasmids pHKK702 and pHKK703 from Enterococcus faecium clinical isolate R7 have been implicated in the conjugal transfer of VmR. pHKK702 is a 41-kb plasmid that contains an element indistinguishable from the glycopeptide-resistance transposon Tn1546. pHKK703 is an approx. 55-kb putative sex pheromone-response plasmid that is required for conjugative mobilization of pHKK702. During experiments in which strain R7 was used as a donor, a highly conjugative VmR transconjugant was isolated that formed constitutive cellular aggregates. Restriction analyses and DNA hybridizations revealed that the transconjugant harbored a single plasmid of approx. 92 kb and this plasmid (pHKK701) was composed of DNA from both pHKK702 and pHKK703. Results from DNA sequence analyses showed that a 39-kb composite transposon (Tn5506) from pHKK702 had inserted into pHKK703. The left end of Tn5506 contained a single insertion sequence (IS) element, IS1216V2, whereas the right end was composed of a tandem IS structure consisting of the novel 1065-bp IS1252 nested within an IS1216V1 element. Transposition of Tn5506 from pHKK702 to pHKK703 created an 8-bp target sequence duplication at the site of insertion and interrupted an ORF (ORFX) that was 91% identical to that of prgX, a gene proposed to negatively regulate sex pheromone response of the E.faecalis plasmid, pCF10. We propose that the interruption of ORFX by Tn5506 led to the constitutive cellular aggregation phenotype and thereby enhanced the efficiency with which VmR was transferred. Similar IS1216V-mediated transposition events may contribute to the horizontal spread of glycopeptide resistance among enterococci in nature.


Asunto(s)
Antibacterianos/farmacología , Conjugación Genética/genética , Enterococcus faecium/efectos de los fármacos , Plásmidos/genética , Vancomicina/farmacología , Secuencia de Aminoácidos , Adhesión Bacteriana/genética , Proteínas Bacterianas/genética , Secuencia de Bases , Elementos Transponibles de ADN/genética , Farmacorresistencia Microbiana/genética , Enterococcus faecium/genética , Datos de Secuencia Molecular , Sistemas de Lectura Abierta/genética , Replicón/genética , Atractivos Sexuales/genética
20.
Drugs ; 35 Suppl 1: 9-14, 1988.
Artículo en Inglés | MEDLINE | ID: mdl-3129275

RESUMEN

Treatment with tiaprofenic acid appreciably reduced the level of plasminogen activators in the medium of 3T3-Balb mouse fibroblasts, as revealed by both a fibrin plate assay and amidolytic determination with chromogenic substrates. At the same time, tiaprofenic acid was able to inhibit the production of plasminogen activators induced by phorbol myristate acetate, a powerful inflammation and tumour promoter, added to the cell monolayers. By isolating the inhibitors of plasminogen activators it was possible to show that the decrease of fibrinolytic activity produced by tiaprofenic acid is not related to an increase of inhibitors. Rather, a decrease of activators seems to take place. Synovial fluid samples from 4 patients before and after treatment with tiaprofenic acid were also assayed for plasminogen activator activity by the fibrin lysis method. In 3 of the 4 cases a marked decrease after treatment was evident. The one unresponsive patient suffered from a para-neoplastic arthritis.


Asunto(s)
Antiinflamatorios no Esteroideos/farmacología , Inflamación/metabolismo , Activadores Plasminogénicos/metabolismo , Propionatos/farmacología , Animales , Artritis Reumatoide/metabolismo , Células Cultivadas , Cromatografía de Afinidad , Ratones , Ratones Endogámicos BALB C , Activadores Plasminogénicos/antagonistas & inhibidores , Inactivadores Plasminogénicos , Líquido Sinovial/metabolismo
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