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1.
Am J Transplant ; 16(7): 2158-71, 2016 07.
Artículo en Inglés | MEDLINE | ID: mdl-26749226

RESUMEN

Facial transplantation is a life-changing procedure for patients with severe composite facial defects. However, skin is the most immunogenic of all transplants, and better understanding of the immunological processes after facial transplantation is of paramount importance. Here, we describe six patients who underwent full facial transplantation at our institution, with a mean follow-up of 2.7 years. Seum, peripheral blood mononuclear cells, and skin biopsy specimens were collected prospectively, and a detailed characterization of their immune response (51 time points) was performed, defining 47 immune cell subsets, 24 serum cytokines, anti-HLA antibodies, and donor alloreactivity on each sample, producing 4269 data points. In a nonrejecting state, patients had a predominant T helper 2 cell phenotype in the blood. All patients developed at least one episode of acute cellular rejection, which was characterized by increases in interferon-γ/interleukin-17-producing cells in peripheral blood and in the allograft's skin. Serum monocyte chemotactic protein-1 level was significantly increased during rejection compared with prerejection time points. None of the patients developed de novo donor-specific antibodies, despite a fourfold expansion in T follicular helper cells at 1 year posttransplantation. In sum, facial transplantation is frequently complicated by a codominant interferon-γ/interleukin-17-mediated acute cellular rejection process. Despite that, medium-term outcomes are promising with no evidence of de novo donor-specific antibody development.


Asunto(s)
Trasplante Facial/efectos adversos , Rechazo de Injerto/diagnóstico , Supervivencia de Injerto/inmunología , Interferón gamma/inmunología , Interleucina-17/inmunología , Células TH1/inmunología , Adulto , Femenino , Estudios de Seguimiento , Tasa de Filtración Glomerular , Rechazo de Injerto/etiología , Humanos , Pruebas de Función Renal , Leucocitos Mononucleares/inmunología , Masculino , Persona de Mediana Edad , Pronóstico , Factores de Riesgo , Receptores de Trasplantes
2.
Br J Cancer ; 112(4): 714-9, 2015 Feb 17.
Artículo en Inglés | MEDLINE | ID: mdl-25611300

RESUMEN

BACKGROUND: LGR5 is an important marker of intestinal stem cells and performs its vital functions at the cell membrane. Despite the importance of LGR5 to both normal and cancer stem cell biology, it is not known how microenvironmental stress affects the expression and subcellular distribution of the protein. METHODS: Nutrient stress was induced through glucose starvation. Glycosylation status was assessed using endoglycosidase or tunicamycin treatment. Flow cytometry and confocal microscopy were used to assess subcellular distribution of LGR5. RESULTS: Glucose deprivation altered the glycosylation status of LGR5 resulting in reduced protein stability and cell surface expression. Furthermore, inhibiting LGR5 glycosylation resulted in depleted surface expression and reduced localisation in the cis-Golgi network. CONCLUSIONS: Nutrient stress within a tumour microenvironment has the capacity to alter LGR5 protein stability and membrane localisation through modulation of LGR5 glycosylation status. As LGR5 surface localisation is required for enhanced Wnt signalling, this is the first report to show a mechanism by which the microenvironment could affect LGR5 function.


Asunto(s)
Adenoma/metabolismo , Membrana Celular/metabolismo , Neoplasias Colorrectales/metabolismo , Glucosa/deficiencia , Células Madre Neoplásicas/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Estrés Fisiológico/fisiología , Adenoma/genética , Adenoma/terapia , Neoplasias Colorrectales/genética , Neoplasias Colorrectales/terapia , Alimentos , Glicosilación , Humanos , Estabilidad Proteica , Transporte de Proteínas , Receptores Acoplados a Proteínas G/genética , Células Tumorales Cultivadas , Microambiente Tumoral
3.
Trends Cell Biol ; 5(9): 361-5, 1995 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-14732079

RESUMEN

The nurse cells in insect ovarioles supply the developing oocytes with various cellular components, including mRNAs, which pass from one cell to the other through intercellular bridges traversed by microtubules. Best studied of these mRNAs are those that encode the axis-determining factors in Drosophila embryos. These mRNAs are further translocated and localized within the oocyte to sites where the products of their translation will ultimately function. This article explores the evidence supportive of a role for microtubules and motor proteins in these processes.

4.
J Cell Biol ; 153(7): 1415-26, 2001 Jun 25.
Artículo en Inglés | MEDLINE | ID: mdl-11425872

RESUMEN

Cytoplasmic dynein is the major minus end-directed microtubule motor in animal cells, and associates with many of its cargoes in conjunction with the dynactin complex. Interaction between cytoplasmic dynein and dynactin is mediated by the binding of cytoplasmic dynein intermediate chains (CD-IC) to the dynactin subunit, p150(Glued). We have found that both CD-IC and p150(Glued) are cleaved by caspases during apoptosis in cultured mammalian cells and in Xenopus egg extracts. Xenopus CD-IC is rapidly cleaved at a conserved aspartic acid residue adjacent to its NH(2)-terminal p150(Glued) binding domain, resulting in loss of the otherwise intact cytoplasmic dynein complex from membranes. Cleavage of CD-IC and p150(Glued) in apoptotic Xenopus egg extracts causes the cessation of cytoplasmic dynein--driven endoplasmic reticulum movement. Motility of apoptotic membranes is restored by recruitment of intact cytoplasmic dynein and dynactin from control cytosol, or from apoptotic cytosol supplemented with purified cytoplasmic dynein--dynactin, demonstrating the dynamic nature of the association of cytoplasmic dynein and dynactin with their membrane cargo.


Asunto(s)
Apoptosis/fisiología , Movimiento Celular/fisiología , Proteínas Asociadas a Microtúbulos/metabolismo , Subunidades de Proteína , Proteínas de Xenopus , Secuencia de Aminoácidos , Animales , Sitios de Unión/efectos de los fármacos , Sitios de Unión/fisiología , Caspasas/metabolismo , Caspasas/farmacología , Membrana Celular/efectos de los fármacos , Membrana Celular/metabolismo , Movimiento Celular/efectos de los fármacos , Clonación Molecular , Complejo Dinactina , Dineínas/genética , Dineínas/metabolismo , Dineínas/farmacología , Retículo Endoplásmico/metabolismo , Células HL-60 , Humanos , Sustancias Macromoleculares , Proteínas Asociadas a Microtúbulos/genética , Datos de Secuencia Molecular , Oocitos/química , Oocitos/metabolismo , Estructura Terciaria de Proteína/efectos de los fármacos , Estructura Terciaria de Proteína/fisiología , Ratas , Alineación de Secuencia , Xenopus
5.
Science ; 218(4571): 483-5, 1982 Oct 29.
Artículo en Inglés | MEDLINE | ID: mdl-7123248

RESUMEN

Qualitatively distinct patterns of cardiovascular and neuroendocrine responses were observed in male college students during mental work and during sensory intake task performance. During mental work, Type A (coronary-prone) subjects showed greater muscle vasodilatation and more enhanced secretion of norepinephrine, epinephrine, and cortisol than Type B subjects. During sensory intake, Type A hyperresponsivity was found for testosterone and, among those subjects with a positive family history of hypertension, for cortisol. As a demonstration of combined cardiovascular, sympathetic nervous system, and neuroendocrine hyperresponsivity to specific cognitive tasks in Type A subjects, this study breaks ground in the search for mechanisms mediating the increased coronary disease risk among Type A persons.


Asunto(s)
Conducta/fisiología , Cognición/fisiología , Presión Sanguínea , Enfermedades Cardiovasculares/etiología , Hemodinámica , Hormonas/sangre , Humanos , Hidrocortisona/sangre , Riesgo
6.
Mol Biol Cell ; 10(6): 1909-22, 1999 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-10359605

RESUMEN

The endoplasmic reticulum (ER) in animal cells uses microtubule motor proteins to adopt and maintain its extended, reticular organization. Although the orientation of microtubules in many somatic cell types predicts that the ER should move toward microtubule plus ends, motor-dependent ER motility reconstituted in extracts of Xenopus laevis eggs is exclusively a minus end-directed, cytoplasmic dynein-driven process. We have used Xenopus egg, embryo, and somatic Xenopus tissue culture cell (XTC) extracts to study ER motility during embryonic development in Xenopus by video-enhanced differential interference contrast microscopy. Our results demonstrate that cytoplasmic dynein is the sole motor for microtubule-based ER motility throughout the early stages of development (up to at least the fifth embryonic interphase). When egg-derived ER membranes were incubated in somatic XTC cytosol, however, ER tubules moved in both directions along microtubules. Data from directionality assays suggest that plus end-directed ER tubule extensions contribute approximately 19% of the total microtubule-based ER motility under these conditions. In XTC extracts, the rate of ER tubule extensions toward microtubule plus ends is lower ( approximately 0.4 microm/s) than minus end-directed motility ( approximately 1.3 microm/s), and plus end-directed motility is eliminated by a function-blocking anti-conventional kinesin heavy chain antibody (SUK4). In addition, we provide evidence that the initiation of plus end-directed ER motility in somatic cytosol is likely to occur via activation of membrane-associated kinesin.


Asunto(s)
Corriente Citoplasmática/fisiología , Retículo Endoplásmico/metabolismo , Cinesinas/metabolismo , Microtúbulos/metabolismo , Xenopus laevis/embriología , Animales , Extractos Celulares , Membrana Celular/metabolismo , Células Cultivadas , Citosol , Dineínas/metabolismo , Embrión no Mamífero/citología , Embrión no Mamífero/metabolismo , Femenino , Óvulo/citología , Óvulo/metabolismo , Xenopus laevis/crecimiento & desarrollo
7.
Biochim Biophys Acta ; 627(2): 144-56, 1980 Jan 17.
Artículo en Inglés | MEDLINE | ID: mdl-6444271

RESUMEN

Phenylalanine in conjunction with p-chlorophenylalanine or alpha-methylphenylalanine was administered to suckling rats to induce hyperphenylalaninemia reminiscent of untreated phenylketonuria, and developmental parameters were monitored. The experimental model utilizing p-chlorophenylalanine was found to be unsatisfactory, in that the drug had general deleterious effects on growth, numerous side effects including increased mortality, and affected brain levels of biogenic monoamine neurotransmitters. The model utilizing alpha-methylphenylalanine was relatively free from nonspecific effects and thus, changes observed in the animals were attributable to experimental phenylketonuria. The latter animals had slightly decreased body and brain weights, and exhibited grossly elevated serum phenylalanine and urinary excretion of phenylketone metabolites. Hyperphenylalaninemia produced greatly disrupted brain amino acids at 10 days of age (prior to the formalization of the blood-brain barrier and specific transport systems) which was limited by 30 days of age to changes in glycine, gamma-aminobutyric acid and the aliphatic and aromatic amino acids which compete for uptake in the brain by a common carrier. These animals also exhibited a myelin deficit and changes in proteins from isolated nerve cell preparations. Mature animals which had daily treatment up to 60 days of age exhibited a long-term learning impairment. These observations are consistent with many aspects of the clinical picture of untreated phenylketonuric patients, and suggest that this animal model will be beneficial in studying the disease.


Asunto(s)
Modelos Animales de Enfermedad , Fenclonina/toxicidad , Fenilalanina/análogos & derivados , Fenilcetonurias/inducido químicamente , Factores de Edad , Aminoácidos/metabolismo , Animales , Conducta Animal/efectos de los fármacos , Peso Corporal/efectos de los fármacos , Química Encefálica/efectos de los fármacos , Humanos , Aprendizaje/efectos de los fármacos , Proteínas de la Mielina/metabolismo , Fenilalanina/farmacología , Ácidos Fenilpirúvicos/sangre , Ratas
8.
Diabetes Care ; 16(8): 1087-94, 1993 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-8375238

RESUMEN

OBJECTIVE: To examine the benefits of relaxation training for patients with NIDDM and to investigate individual differences that could predict a positive response to relaxation training. RESEARCH DESIGN AND METHODS: Thirty-eight subjects with NIDDM were treated with intensive conventional diabetes therapy after an initial metabolic evaluation and psychological and pharmacological testing. Half were assigned to also receive biofeedback-assisted relaxation training. Treatment effects on GHb levels and glucose tolerance were evaluated after 8 wk. RESULTS: Subjects demonstrated significant improvements in GHb level, but not in glucose tolerance, after 8 wk of intensive conventional treatment. These improvements persisted throughout the follow-up period. However, the group provided with relaxation training did not experience greater improvements on either measure than the group given conventional diabetes treatment only. Within the group that received relaxation training, correlations occurred between the improvements in glucose tolerance after treatment and individual differences in trait anxiety and in the effect of alprazolam on glucose tolerance. Differences in the effects of EPI on glucose tolerance and personality measures of neuroticism and perceived locus of control also appeared to be related to improvements in glucose tolerance after training. CONCLUSIONS: Relaxation training did not confer added benefit over and above that provided by conventional diabetes treatment for patients with NIDDM. Additional research is needed to determine whether the administration of relaxation training to selected patients, especially those who are most responsive to stress, would provide benefits for glucose control that are not achieved by conventional treatment.


Asunto(s)
Glucemia/metabolismo , Diabetes Mellitus Tipo 2/psicología , Terapia por Relajación , Análisis de Varianza , Ansiedad , Biorretroalimentación Psicológica , Presión Sanguínea , Diabetes Mellitus Tipo 2/fisiopatología , Diabetes Mellitus Tipo 2/terapia , Epinefrina/sangre , Femenino , Estudios de Seguimiento , Prueba de Tolerancia a la Glucosa , Hemoglobina Glucada/análisis , Humanos , Control Interno-Externo , Masculino
9.
Diabetes Care ; 20(10): 1539-42, 1997 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-9314631

RESUMEN

OBJECTIVE: Insulin lispro is a rapid-acting analog of human insulin that can be used to target the postprandial rise in plasma glucose. We designed an open-label randomized crossover study of type 2 diabetic patients with secondary failure of sulfonylurea therapy to determine whether improvement of postprandial hyperglycemia would affect total daily glucose control. RESEARCH DESIGN AND METHODS: Twenty-five type 2 diabetic patients who were poorly controlled on a maximum dose of sulfonylureas were studied in a university hospital clinical research center. In one arm of the study, patients continued therapy with maximum-dose sulfonylureas. In the other arm, patients used a combination therapy with insulin lispro before meals and sulfonylureas. After 4 months, patients were crossed over to the opposite arm. Fasting plasma glucose (FPG) and 1- and 2-h postprandial glucose (after a standardized meal), HbA1c, total, HDL, and LDL cholesterol, and triglyceride levels were measured at the end of each arm of the study. RESULTS: Insulin lispro in combination with sulfonylurea therapy significantly reduced 2-h postprandial glucose concentrations compared with sulfonylureas alone, from 18.6 to 14.2 mmol/l (P < 0.0001), and incremental postprandial glucose area from 617.8 to 472.9 mmol.min.1-1 (P < 0.0007). FPG levels were decreased from 10.9 to 8.5 mmol/l (P < 0.0001), and HbA1c values were reduced form 9.0 to 7.1% (P < 0.0001). Total cholesterol was significantly decreased in the lispro arm from 5.44 to 5.10 mmol/l (P < 0.02). HDL cholesterol concentrations were increased in the lispro arm from 0.88 to 0.96 mmol/l (P < 0.01). The patients weighed significantly more after lispro therapy than after sulfonylureas alone, but the difference was small in absolute terms (sulfonylurea therapy alone, 90.6 kg; lispro therapy, 93.8 kg; P < 0.0001). Two episodes of hypoglycemia (glucose concentrations, < 2.8 mmol/l) were reported by the patients while using lispro. CONCLUSIONS: Previously, it has not been possible to address the effect of treatment of postprandial hyperglycemia specifically. We have now shown that the treatment of postprandial hyperglycemia with insulin lispro markedly improves overall glucose control and some lipid parameters in patients with type 2 diabetes.


Asunto(s)
Glucemia/efectos de los fármacos , Diabetes Mellitus Tipo 2/sangre , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Hipoglucemiantes/uso terapéutico , Insulina/análogos & derivados , Periodo Posprandial , Adulto , Anciano , Glucemia/metabolismo , Péptido C/sangre , Colesterol/sangre , HDL-Colesterol/sangre , Femenino , Humanos , Insulina/uso terapéutico , Insulina Lispro , Masculino , Persona de Mediana Edad , Compuestos de Sulfonilurea/uso terapéutico , Triglicéridos/sangre
10.
Diabetes Care ; 23(9): 1321-5, 2000 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-10977026

RESUMEN

OBJECTIVE: To determine whether traits of normal personality are associated with variations in glycemic control in patients with type 2 diabetes. RESEARCH DESIGN AND METHODS: A longitudinal cohort study was conducted using data from 105 type 2 diabetic patients in a clinical trial of a stress management intervention. Before treatment assignment, patients completed the NEO Personality Inventory, Revised, which is a questionnaire inventory measuring 5 major domains of normal personality and 30 important traits that define these domains. Glycemic control was assessed by measures of HbA1c and average blood glucose levels based on 7 days of self-monitoring at baseline and at 6 and 12 months. Relationships between personality traits and measures of glycemic control were examined by correlation and linear regression models that were adjusted for age, sex, race, duration of diabetes, medication status, and experimental treatment. RESULTS: Lower average blood glucose values at baseline were associated with higher scores for the personality domain of neuroticism and several specific traits including anxiety, angry hostility depression, self-consciousness, and vulnerability but were associated with lower scores for the trait of altruism. Results were similar for HbA1c but were not as strong. Follow-up results were similar but were less consistent. CONCLUSIONS: Personality traits may offer new insights into variations in glycemic control in patients with type 2 diabetes undergoing standard management. The relative tendency to experience fewer negative emotions and to focus on the needs of others instead of oneself could prove to be a risk factor for poor glycemic control.


Asunto(s)
Glucemia/metabolismo , Diabetes Mellitus Tipo 2/sangre , Diabetes Mellitus Tipo 2/psicología , Personalidad , Adulto , Afecto , Terapia Conductista , Automonitorización de la Glucosa Sanguínea , Estudios de Cohortes , Femenino , Hemoglobina Glucada/análisis , Humanos , Estudios Longitudinales , Masculino , Inventario de Personalidad , Estrés Psicológico/prevención & control , Encuestas y Cuestionarios
11.
Clin Pharmacol Ther ; 32(6): 765-8, 1982 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-7140140

RESUMEN

We determined the effects of cigarette deprivation and smoking on saliva cortisol levels in the presence and absence of an operant, monetarily reinforced work task. Subjects were randomly exposed to the following four experimental conditions over successive sessions: no smoking, smoking, no smoking + work, and smoking + work. Measurements of cortisol levels in saliva were determined before and after each daily session. Saliva cortisol levels declined from the beginning to the end of sessions and the end-of-session saliva cortisol levels were not affected by any of the four experimental conditions. Increased cigarette smoking in the presence of the work task also did not affect saliva cortisol levels. Our data do not support: reports of increased cortisol levels as a consequence of smoking or theories relating cortisol and endorphin release to nicotine habituation.


Asunto(s)
Hidrocortisona/análisis , Saliva/análisis , Fumar , Adulto , Condicionamiento Operante , Humanos , Masculino , Persona de Mediana Edad
12.
Neuropsychopharmacology ; 1(4): 337-40, 1988 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-3251510

RESUMEN

beta-Adrenergic hyperreactivity has been proposed as a pathogenic mechanism of increased coronary risk in Type A individuals. This study compared the effects of propranolol, diazepam, and placebo on cardiovascular and neuroendocrine responses to a stressful cognitive task in six young Type A males. Although diazepam did not differ from placebo, propranolol attenuated heart rate and norepinephrine responses and enhanced cortisol responses to the task. Findings suggest that propranolol has reciprocal effects on the norepinephrine and cortisol components of the "fight-flight" response. Possible central nervous system mechanisms are described.


Asunto(s)
Diazepam/farmacología , Epinefrina/metabolismo , Hemodinámica/efectos de los fármacos , Hormonas/metabolismo , Norepinefrina/metabolismo , Propranolol/farmacología , Estrés Psicológico/fisiopatología , Adulto , Diástole/efectos de los fármacos , Método Doble Ciego , Epinefrina/sangre , Hormona del Crecimiento/metabolismo , Frecuencia Cardíaca/efectos de los fármacos , Hormonas/sangre , Humanos , Hidrocortisona/metabolismo , Masculino , Matemática , Norepinefrina/sangre , Prolactina/metabolismo , Valores de Referencia , Flujo Sanguíneo Regional/efectos de los fármacos , Sístole/efectos de los fármacos , Testosterona/metabolismo , Resistencia Vascular/efectos de los fármacos
13.
Am Heart J ; 142(5): 760-9, 2001 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11685160

RESUMEN

BACKGROUND: Patients undergoing percutaneous coronary intervention (PCI) for unstable coronary syndromes have substantial emotional and spiritual distress that may promote procedural complications. Noetic (nonpharmacologic) therapies may reduce anxiety, pain and distress, enhance the efficacy of pharmacologic agents, or affect short- and long-term procedural outcomes. METHODS: The Monitoring and Actualization of Noetic Training (MANTRA) pilot study examined the feasibility of applying 4 noetic therapies-stress relaxation, imagery, touch therapy, and prayer-to patients in the setting of acute coronary interventions. Eligible patients had acute coronary syndromes and invasive angiography or PCI. Patients were randomized across 5 treatment groups: the 4 noetic and standard therapies. Questionnaires completed before PCI reflected patients' religious beliefs and anxiety. Index hospitalization end points included post-PCI ischemia, death, myocardial infarction, heart failure, and urgent revascularization. Mortality was followed up for 6 months after hospitalization. RESULTS: Of eligible patients, 88% gave informed consent. Of 150 patients enrolled, 120 were assigned to noetic therapy; 118 (98%) completed their therapeutic assignments. All clinical end points were available for 100% of patients. Results were not statistically significant for any outcomes comparisons. There was a 25% to 30% absolute reduction in adverse periprocedural outcomes in patients treated with any noetic therapy compared with standard therapy. The lowest absolute complication rates were observed in patients assigned to off-site prayer. All mortality by 6-month follow-up was in the noetic therapies group. In patients with questionnaire scores indicating a high level of spiritual belief, a high level of personal spiritual activity, a low level of community-based religious involvement, or a high level of anxiety, noetic therapies appeared to show greater reduction in absolute in-hospital complication rates compared with standard therapy. CONCLUSIONS: Acceptance of noetic adjuncts to invasive therapy for acute coronary syndromes was excellent, and logistics were feasible. No outcomes differences were significant; however, index hospitalization data consistently suggested a therapeutic benefit with noetic therapy. Of all noetic therapies, off-site intercessory prayer had the lowest short- and long-term absolute complication rates. Definitive demonstration of treatment effects of this magnitude would be feasible in a patient population about 4 times that of this pilot study. Absolute mortality differences make safety considerations a mandatory feature of future clinical trials in this area.


Asunto(s)
Enfermedad Coronaria/psicología , Enfermedad Coronaria/cirugía , Angioplastia Coronaria con Balón/psicología , Puente de Arteria Coronaria/psicología , Estudios de Factibilidad , Humanos , Curación Mental/psicología , Proyectos Piloto , Resultado del Tratamiento
14.
Am J Kidney Dis ; 36(2): 419-33, 2000 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-10922324

RESUMEN

The number of high-risk patients undergoing renal biopsy is likely to increase in the near future because of the increased use of anticoagulants for such conditions as atrial fibrillation, combined liver and kidney disease caused by hepatitis C, and the aging of the population. Nephrologists need to become increasingly familiar with evaluating such patients through both specialized management of percutaneous kidney biopsy and alternate methods of renal biopsy, which primarily consist of open (surgical) biopsy, transjugular (transvenous) biopsy, and laparoscopic biopsy. The indications, complications, and general approach to such patients are discussed. This is a US government work. There are no restrictions on its use.


Asunto(s)
Biopsia , Riñón/patología , Biopsia/efectos adversos , Biopsia/métodos , Biopsia con Aguja/efectos adversos , Contraindicaciones , Humanos , Factores de Riesgo
15.
Psychopharmacology (Berl) ; 82(4): 282-6, 1984.
Artículo en Inglés | MEDLINE | ID: mdl-6427814

RESUMEN

Responding by six rats was maintained under a concurrent chained fixed-ratio 1, fixed-ratio 9 schedule (conc chain FR1 FR9 ) of food, water, and morphine presentations. The subjects had continuous access to the schedule contingencies on a reversed 12-h light-dark cycle. Local rates and temporal patterns were very similar for responding maintained by the three reinforcers with food and water intake occurring predominantly during the dark cycle, while morphine infusions were evenly distributed. Food and water extinction (24-h duration) decreased the number of ratios completed on both the food and water levers. Moreover, food extinction resulted in a large increase in I.V. morphine self-administration. Morphine extinction increased responding on the morphine lever while almost eliminating responding on the water lever. Changes in the dose of morphine (2.5-40 mg/kg/injection) did not significantly affect food and water intake, but were inversely related to responding on the morphine lever. Saline substitutions resulted in effects similar to those observed during morphine extinction. The schedule used in this study provides a method for examining the specificity of a number of pharmacological and neurochemical manipulations.


Asunto(s)
Condicionamiento Operante/fisiología , Morfina/farmacología , Refuerzo en Psicología , Animales , Condicionamiento Operante/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Extinción Psicológica/efectos de los fármacos , Alimentos , Inyecciones Intravenosas , Masculino , Morfina/administración & dosificación , Ratas , Ratas Endogámicas F344 , Esquema de Refuerzo , Factores de Tiempo , Agua
16.
Neuropeptides ; 5(1-3): 37-40, 1984 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-6543384

RESUMEN

Rats trained to discriminate pentylenetetrazol (PTZ) from saline in a two-lever food-reinforced operant task were given a three-day course of morphine, 15 to 45 mg/kg tid, ip. On the third day naloxone produced dose-dependent generalization to the PTZ stimulus, with 66% of subjects selecting the PTZ lever after the highest dose (0.32 mg/kg). Following termination of morphine injections, generalization of spontaneous withdrawal was tested. Approximately 50% of subjects selected the PTZ lever at 24 and 48 hrs after the last morphine, and by 96 hrs the percentage of subjects selecting the PTZ lever had dropped to 11%. Rats that chose the PTZ lever at 48 hrs were given diazepam, 5.0 mg/kg, which blocked the PTZ-like stimulus. These data demonstrate that morphine withdrawal produces a stimulus with PTZ-like characteristics which can be blocked by an anxiolytic, and they suggest that the PTZ discrimination may have general utility for investigating drug dependence and withdrawal in animals.


Asunto(s)
Morfina/toxicidad , Pentilenotetrazol/farmacología , Síndrome de Abstinencia a Sustancias/psicología , Animales , Discriminación en Psicología , Humanos , Masculino , Dependencia de Morfina/psicología , Ratas
17.
Brain Res ; 701(1-2): 142-50, 1995 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-8925277

RESUMEN

This experiment tested the hypotheses that: (1) self-administration of cocaine would produce an increase in dopamine (DA) oxidation current in the nucleus accumbens (n. acc.); and (2) a faster rate of cocaine intake in the presence of a D1 receptor antagonist would produce a greater increase in DA levels. Rats trained to self-administer cocaine under a fixed-ratio 2 schedule were implanted with stearate-modified graphite paste electrodes bilaterally in the n. acc. The effect of pretreatment with the D1 receptor antagonist, SCH23390, on the DA oxidation current associated with self-administration of cocaine (1 mg/inj.) or saline was investigated using chronoamperometry. Pretreatment with SCH23390 produced a 2-fold increase in the amount of cocaine intake. This in turn resulted in a 2-fold increase in the DA oxidation current recorded in the n. acc. Pretreatment with SCH23390 did not, however, produce any significant change in either the number of saline injections received or the DA oxidation current recorded during saline self-administration. These findings show that cocaine increases DA oxidation currents in the n. acc., and that both the rate of cocaine self-administration and the magnitude of these currents increase even further following SCH23390. The results also imply that the baseline rate of cocaine self-administration does not result in the occupation of all possible DA transporter sites.


Asunto(s)
Benzazepinas/farmacología , Cocaína/farmacología , Antagonistas de Dopamina/farmacología , Inhibidores de Captación de Dopamina/farmacología , Dopamina/metabolismo , Animales , Condicionamiento Operante/efectos de los fármacos , Electroquímica , Electrodos Implantados , Masculino , Núcleo Accumbens/química , Núcleo Accumbens/efectos de los fármacos , Núcleo Accumbens/metabolismo , Oxidación-Reducción , Ratas , Esquema de Refuerzo , Autoadministración
18.
Brain Res ; 240(1): 95-108, 1982 May 20.
Artículo en Inglés | MEDLINE | ID: mdl-7201340

RESUMEN

The content and turnover of dopamine, norepinephrine and 5-hydroxytryptamine (serotonin), and the content of their respective major metabolites were evaluated in 19 discrete brain areas of rats exposed to conditioned emotional response (CER), and in control groups which received either equivalent yoked shock (shock only) or compound stimulus presentation (tone only). On test day, CER animals suppressed responding and exhibited forms of emotional behavior after presentation of the conditioned stimulus (CS); while shock only and tone only control groups, and CER animals which received an acute dose of diazepam prior to testing, did not suppress. Few changes were observed in content of the biogenic amines or their metabolites, suggesting that the behavioral manipulations were acting within normal physiological limits. On the other hand, numerous changes were observed in the utilization of the 3 biogenic monoamines, which were correlated with the conditioning-anxiety (comparisons of CER vs shock only) and the shock history (comparison of shock only vs tone only). These observations are consistent with putative neural pathways in the frontal cortex, septum, nucleus accumbens, amygdala, striatum, hippocampus and brain stem (which utilize specific monoamines), and with discrete brain areas which have been implicated in classical conditioning and CER-related phenomena. These observations suggest roles for biogenic monoamines in mediating or responding to the classical conditioning and emotional components of the paradigm.


Asunto(s)
Aminas Biogénicas/metabolismo , Encéfalo/metabolismo , Condicionamiento Psicológico/fisiología , Emociones/fisiología , Animales , Ansiedad/fisiología , Dopamina/metabolismo , Humanos , Masculino , Norepinefrina/metabolismo , Ratas , Ratas Endogámicas F344 , Serotonina/metabolismo , Distribución Tisular
19.
Eur J Pharmacol ; 65(2-3): 313-5, 1980 Jul 25.
Artículo en Inglés | MEDLINE | ID: mdl-7190503

RESUMEN

In this report evidence is presented that amantadine hydrochloride greatly reduced the development of dopaminergic receptor hypersensitivity in the striatum, which normally results following chronic haloperidol administration using both a stereotyped behavior bioassay and a [3H]spiroperidol receptor binding assay. Amantadine prophylaxis reduced maximal ligand binding to near control levels and also significantly reduced apomorphine induced stereotypy. These results clearly demonstrate that amantadine greatly reduced haloperidol-induced striatal dopamine receptor hypersensitivity and support the hypothesis that amantadine given concurrently with neuroleptic agents might serve to prevent the development of human tardive dyskinesia.


Asunto(s)
Amantadina/farmacología , Cuerpo Estriado/metabolismo , Haloperidol/antagonistas & inhibidores , Receptores Dopaminérgicos/efectos de los fármacos , Animales , Apomorfina/farmacología , Cuerpo Estriado/efectos de los fármacos , Haloperidol/farmacología , Humanos , Técnicas In Vitro , Cinética , Ratas , Espiperona/metabolismo , Conducta Estereotipada/efectos de los fármacos
20.
Eur J Pharmacol ; 83(3-4): 183-90, 1982 Sep 24.
Artículo en Inglés | MEDLINE | ID: mdl-6293838

RESUMEN

Groups of littermate rats were trained to respond for food reinforcement on a variable interval one-min (VI 1) schedule, after which they were classically conditioned to associate a conditioned stimulus (CS) with footshock (conditioned emotional response; conditioned suppression; CER). Two control groups received yoked footshock (no CS) or the visual-auditory stimulus only (no footshock). On test day, a group of the CER conditioned animals received injections of either vehicle or diazepam prior to exposure to the VI 1 food-reinforced schedule. After 30 min of the VI 1 schedule, the CS was presented continuously for 15 min, after which the animals were decapitated, the brains removed, membranes prepared and in vitro receptor binding evaluated. During the CS, the CER animals suppressed responding and exhibited conditioned fear (emotional) behavior, while the control groups, and animals given acute diazepam, maintained normal responding. [3H]Diazepam binding was reduced in the CER animals, yet acute benzodiazepine administration did not effect this binding. [3H]QNB binding was reduced by CER and increased by diazepam administration. Adrenergic, serotonergic and dopaminergic systems were also evaluated. Traditional biogenic amine systems may respond to CER and diazepam administration in some compensatory manner.


Asunto(s)
Aminas Biogénicas/metabolismo , Condicionamiento Psicológico/fisiología , Diazepam/farmacología , Receptores de Superficie Celular/metabolismo , Animales , Condicionamiento Psicológico/efectos de los fármacos , Masculino , Ratas , Ratas Endogámicas F344 , Receptores de Superficie Celular/efectos de los fármacos , Receptores de GABA-A , Receptores Muscarínicos/efectos de los fármacos , Receptores Muscarínicos/metabolismo , Receptores de Neurotransmisores/efectos de los fármacos , Receptores de Neurotransmisores/metabolismo
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