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1.
Angew Chem Int Ed Engl ; 61(31): e202206900, 2022 08 01.
Artículo en Inglés | MEDLINE | ID: mdl-35652453

RESUMEN

The modification of surfaces with multiple ligands allows the formation of platforms for the study of multivalency in diverse processes. Herein we use this approach for the implementation of a photosensitizer (PS)-nanocarrier system that binds efficiently to siglec-10, a member of the CD33 family of siglecs (sialic acid (SA)-binding immunoglobulin-like lectins). In particular, a zinc phthalocyanine derivative bearing three SA moieties (PcSA) has been incorporated in the membrane of small unilamellar vesicles (SUVs), retaining its photophysical properties upon insertion into the SUV's membrane. The interaction of these biohybrid systems with human siglec-10-displaying supported lipid bilayers (SLBs) has shown the occurrence of weakly multivalent, superselective interactions between vesicle and SLB. The SLB therefore acts as an excellent cell membrane mimic, while the binding with PS-loaded SUVs shows the potential for targeting siglec-expressing cells with photosensitizing nanocarriers.


Asunto(s)
Liposomas , Lectinas Similares a la Inmunoglobulina de Unión a Ácido Siálico , Membrana Celular/metabolismo , Humanos , Ligandos , Lectinas Similares a la Inmunoglobulina de Unión a Ácido Siálico/metabolismo
2.
Langmuir ; 36(42): 12745-12754, 2020 Oct 27.
Artículo en Inglés | MEDLINE | ID: mdl-33074008

RESUMEN

In this paper, we obtain maps of the spatial tunnel barrier variations in self-assembled monolayers of organosulfurs on Au(111). Maps down to the sub-nanometer scale are obtained by combining topographic scanning tunneling microscopy images with dI/dz spectroscopy. The square root of the tunnel barrier height is directly proportional to the local work function and the dI/dz signal. We use ratios of the tunnel barriers to study the work function contrast in various decanethiol phases: the lying-down striped ß phase, the dense standing-up φ phase, and the oxidized decanesulfonate λ phase. We compare the induced work function variations too: the work function contrast induced by a lying-down striped phase in comparison to the modulation induced by the standing-up φ phase, as well as the oxidized λ phase. By performing these comparisons, we can account for the similarities and differences in the effects of the mechanisms acting on the surface and extract valuable insights into molecular binding to the substrate. The pillow effect, governing the lowering of the work function due to lying-down molecular tails in the striped low density phases, seems to have quite a similar contribution as the surface dipole effect emerging in the dense standing-up decanethiol phases. The dI/dz spectroscopy map of the nonoxidized ß phase compared to the map of the oxidized λ phase indicates that the strong binding of molecules to the substrate is no longer present in the latter.

3.
Crit Rev Food Sci Nutr ; 60(14): 2446-2459, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-31366215

RESUMEN

Irvingia gabonensis, also known as 'bush mango', is a multipurpose fruit tree, native to tropical Africa. It is a priority indigenous fruit tree in western and central Africa since its wood is used for making utensils and fruits are mostly used as food and medicine. The objective of this work is to provide an updated review of the available knowledge about physicochemical characteristics of I. gabonensis fruit in order to evaluate its potential use in the food industry. The fruit mesocarp contains various phytochemicals and ascorbic acid concentration higher than some vitamin C rich fruits, then it is consumed fresh or dried, used to produce juice and wine, or as a flavourant. I. gabonensis fruit kernel is rich in oil (63%-69% crude fat), mainly composed of myristic and lauric acids. Its triacylglycerol composition and, resultantly, melting curve and polymorphism indicate an aptitude for diverse applications, as it is solid at room temperature. Forty-one phenolic compounds were identified in the seeds and derived extracts and supplements, being ellagic acid and its derivates the most present. This review enhances our knowledge about nutritional content and health benefits of I. gabonensis whole fruit, especially its pulp and seed, evidencing the need for safer and more efficient production of value-added products.


Asunto(s)
Celulosa/química , Industria de Alimentos , Frutas/química , África , Humanos
4.
BJOG ; 122(1): 80-91, 2015 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-25209926

RESUMEN

OBJECTIVE: To evaluate the effectiveness of 200 mg of daily vaginal natural progesterone to prevent preterm birth in women with preterm labour. DESIGN: Multicentre, randomised, double-blind, placebo-controlled trial. SETTING: Twenty-nine centres in Switzerland and Argentina. POPULATION: A total of 385 women with preterm labour (24(0/7) to 33(6/7) weeks of gestation) treated with acute tocolysis. METHODS: Participants were randomly allocated to either 200 mg daily of self-administered vaginal progesterone or placebo within 48 hours of starting acute tocolysis. MAIN OUTCOME MEASURES: Primary outcome was delivery before 37 weeks of gestation. Secondary outcomes were delivery before 32 and 34 weeks, adverse effects, duration of tocolysis, re-admissions for preterm labour, length of hospital stay, and neonatal morbidity and mortality. The study was ended prematurely based on results of the intermediate analysis. RESULTS: Preterm birth occurred in 42.5% of women in the progesterone group versus 35.5% in the placebo group (relative risk [RR] 1.2; 95% confidence interval [95% CI] 0.93-1.5). Delivery at <32 and <34 weeks did not differ between the two groups (12.9 versus 9.7%; [RR 1.3; 95% CI 0.7-2.5] and 19.7 versus 12.9% [RR 1.5; 95% CI 0.9-2.4], respectively). The duration of tocolysis, hospitalisation, and recurrence of preterm labour were comparable between groups. Neonatal morbidity occurred in 44 (22.8%) cases on progesterone versus 35 (18.8%) cases on placebo (RR: 1.2; 95% CI 0.82-1.8), whereas there were 4 (2%) neonatal deaths in each study group. CONCLUSION: There is no evidence that the daily administration of 200 mg vaginal progesterone decreases preterm birth or improves neonatal outcome in women with preterm labour.


Asunto(s)
Peso al Nacer , Trabajo de Parto Prematuro/tratamiento farmacológico , Nacimiento Prematuro/prevención & control , Progesterona/uso terapéutico , Progestinas/uso terapéutico , Administración Intravaginal , Adulto , Puntaje de Apgar , Método Doble Ciego , Femenino , Humanos , Indometacina/uso terapéutico , Lactante , Mortalidad Infantil , Recién Nacido , Unidades de Cuidado Intensivo Neonatal/estadística & datos numéricos , Embarazo , Segundo Trimestre del Embarazo , Tercer Trimestre del Embarazo , Receptores de Oxitocina/antagonistas & inhibidores , Tocolíticos/uso terapéutico , Adulto Joven
5.
ACS Cent Sci ; 6(12): 2311-2318, 2020 Dec 23.
Artículo en Inglés | MEDLINE | ID: mdl-33376792

RESUMEN

Understanding how emerging influenza viruses recognize host cells is critical in evaluating their zoonotic potential, pathogenicity, and transmissibility between humans. The surface of the influenza virus is covered with hemagglutinin (HA) proteins that can form multiple interactions with sialic acid-terminated glycans on the host cell surface. This multivalent binding affects the selectivity of the virus in ways that cannot be predicted from the individual receptor-ligand interactions alone. Here, we show that the intrinsic structural and energetic differences between the interactions of avian- or human-type receptors with influenza HA translate from individual site affinity and orientation through receptor length and density on the surface into virus avidity and specificity. We introduce a method to measure virus avidity using receptor density gradients. We found that influenza viruses attached stably to a surface at receptor densities that correspond to a minimum number of approximately 8 HA-glycan interactions, but more interactions were required if the receptors were short and human-type. Thus, the avidity and specificity of influenza viruses for a host cell depend not on the sialic acid linkage alone but on a combination of linkage and the length and density of receptors on the cell surface. Our findings suggest that threshold receptor densities play a key role in virus tropism, which is a predicting factor for both their virulence and zoonotic potential.

6.
Transplant Proc ; 40(6): 1877-80, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-18675077

RESUMEN

Progress in diagnosis and treatment has led to an increased number of transplantation patients who consequently have immunological depression and emergence of tumors. The incidence of cervical neoplasia, according to previous studies, is 11%; this tumor is the only one that can be investigated by screening before and after a graft. Our purpose was to evaluate whether transplanted patients showed an increased incidence of genital human papilloma virus (HPV) infection and whether this infection produced greater progression of disease in cases of low-risk HPV infections. Our study involved 151 transplant patients who underwent Papanicolaou (Pap) and HPV tests. Patients listed for grafts underwent Pap and HPV tests 6 months before and 6 months after transplantation. All patients had negative Pap tests before their grafts. After their grafts 16 patients (10.59%) had negative Pap tests, but positive viral typing. Eleven patients (7.28%) showed positive Pap tests, 6 of whom had low-grade squamous intraepithelial lesion (SIL) and 5 patients high-grade SIL. The final HPV infection incidence (15.23%) was consistent with the literature. The incidence of lower female genital tract intraepithelial lesions (7.28%) was higher than the healthy population or analogous studies (4.5%-8.5%). We showed a constant association between high-risk HPV infection and gynecologic intraepithelial neoplasia, whereas there was no association between low-risk broods HPV infection and neoplasia. In conclusion, screening should start at almost 6 months before grafting to avoid an irreversible situation that is difficult to treat.


Asunto(s)
Trasplante de Riñón/efectos adversos , Infecciones por Papillomavirus/epidemiología , Complicaciones Posoperatorias/clasificación , Displasia del Cuello del Útero/epidemiología , Neoplasias del Cuello Uterino/epidemiología , Adulto , Anciano , Femenino , Humanos , Inmunosupresores/efectos adversos , Incidencia , Trasplante de Riñón/inmunología , Persona de Mediana Edad , Prueba de Papanicolaou , Papillomaviridae/aislamiento & purificación , Neoplasias del Cuello Uterino/patología , Frotis Vaginal , Displasia del Cuello del Útero/patología
7.
Int J Clin Pharmacol Ther ; 45(6): 307-18, 2007 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-17595888

RESUMEN

OBJECTIVE: Application-site disorders are well-known adverse events (AEs) associated with subcutaneous (s.c.) injection. With high-dose, high-frequency interferon (IFN)-beta1a (Rebif) these AEs are generally mild but may lead to the discontinuation of some patients. The objective of this study was to compare the safety, tolerability, and the pharmacokinetic (PK) and pharmacodynamic (PD) profiles of two new formulations of Rebif (Rebif New Formulation: RNF1 and RNF2) with the current formulation (hereafter referred to as R) and placebo. METHODS: In this double-blind, placebo-controlled, parallel-group, Phase I study, healthy volunteers of both sexes were randomized 1:1:1:1 to receive a single 0.5 ml s.c. dose of RNF1, RNF2, R or placebo (normal saline). The three active treatments contained 44 microg IFN-beta1a. During the 24-hour post-dose period, safety and tolerability assessments were conducted and blood samples were taken at regular intervals for PK and PD analyses. Pain intensity on injection was measured using the short-form McGill questionnaire and a 100 mm visual analogue scale (VAS). Further safety assessments were performed and blood samples taken at 24-hour intervals until Day 7 post-dose, with a final post-study visit 10- 14 days after dosing. RESULTS: A total of 48 subjects (22 men, 26 women) were recruited and allocated equally to each treatment (12 subjects per group). AEs were reported by 10 subjects in each active treatment group and by 3 subjects in the placebo group. All AEs were consistent with the known safety profile of R. The number of treatment-emergent AEs was lower in the RNF2 group than the RNF 1 or R groups (21, 31 and 33 events, respectively). Redness at the injection site was mostly mild and occurred in fewer subjects in the RNF2 group (n = 3) than the RNF 1 or R groups (n = 7 and n = 4, respectively). Injection site pain was reported by 1 subject in the RNF2 group, compared with 4, 6 and 3 subjects, respectively, in the RNF1, R and placebo groups. The worst pain intensity, as measured by VAS, was lower in the RNF2 and RNFI groups than either the R or placebo groups. There was considerable intersubject variability in the PK and PD profiles of the three formulations of IFN-beta1a. Nevertheless, the PK and PD characteristics of RNF2 were similar to those of R. CONCLUSIONS: The results from this study suggest that RNF2 may offer improved tolerability compared with the current formulation of R, but retains comparable pharmacokinetic and pharmacodynamic characteristics.


Asunto(s)
Interferón gamma/farmacología , Interferón gamma/farmacocinética , Adolescente , Adulto , Área Bajo la Curva , Química Farmacéutica , Método Doble Ciego , Femenino , Semivida , Humanos , Concentración de Iones de Hidrógeno , Inyecciones Subcutáneas , Interferón gamma/efectos adversos , Masculino , Persona de Mediana Edad , Neopterin/sangre , Dolor/inducido químicamente , Dolor/epidemiología , Dimensión del Dolor/efectos de los fármacos , Proteínas Recombinantes , Encuestas y Cuestionarios , Resultado del Tratamiento , Microglobulina beta-2/sangre
8.
Food Res Int ; 92: 40-47, 2017 02.
Artículo en Inglés | MEDLINE | ID: mdl-28290296

RESUMEN

The purpose of the present study is to compare the effects of four different breads (one commercial par-baked wheat bread, three sourdough breads prepared with commercial wheat flour, organic wheat flour, organic einkorn flour) in 16 healthy subjects. The primary outcome of this randomized cross-over trial was evaluating intra-individual changes in glycemic areas-under-the-curve (AUCs) after 50g carbohydrate portions of each bread; secondary outcomes were changes in insulin, fatty free acids (FFA), triglyceride, acylated ghrelin and satiety AUCs. Blood samples and satiety ratings were collected every 30-min for 2-h after the consumption of each bread. The einkorn flour showed the lowest amylase activity, the commercial flour the highest; commercial bread had the highest carbohydrate content and the lowest dietary fiber content. Glucose AUCs were significantly lower after the consumption of sourdough breads made with organic (12,754±1433mg/dL×h) and einkorn flour (12,216±1210mg/dL×h), with respect to the commercial bread (13,849±2193mg/dL×h). Insulin AUCs decreased after the consumption of all sourdough breads when compared to commercial bread. FFA and triglyceride AUCs did not differ by kind of breads. Median ghrelin AUC was significantly lower and satiety higher after the einkorn bread (3710pg/mL×h; 3225±2414, respectively) than after commercial bread consumption (4140pg/mL×h; 1706±1766, respectively), but not with other sourdough breads. In conclusion, the use of sourdough may improve the nutritional features of breads; einkorn bread induced the least disturbance in carbohydrate homeostasis and the greater satiety. If confirmed by further research, these results might have implications in the approach towards chronic dysmetabolic diseases.


Asunto(s)
Glucemia/metabolismo , Pan , Ácidos Grasos no Esterificados/sangre , Ghrelina/sangre , Insulina/sangre , Saciedad , Triglicéridos/sangre , Adulto , Estudios Cruzados , Dieta , Carbohidratos de la Dieta/análisis , Grasas de la Dieta/análisis , Fibras de la Dieta , Proteínas en la Dieta/análisis , Método Doble Ciego , Femenino , Harina , Humanos , Masculino , Persona de Mediana Edad , Triticum/química , Circunferencia de la Cintura , Adulto Joven
9.
Neuropharmacology ; 29(12): 1103-10, 1990 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-1963475

RESUMEN

The diuretic amiloride has been suggested as a specific inhibitor of T-type neuronal Ca2+ channels. The effects of amiloride on glutamate receptor-gated cationic channels and glutamate-induced. Ca2(+)-dependent neuronal death were investigated in primary neuronal cultures from neonatal rats. In primary cultures of cerebellar granule neurons of the rat, receiving 50 microM glutamate for 15 min, at 22 degrees C, in the absence of Mg2+, about 80% of neurons were killed in about 24 hr. Exposure of neurons to such a pulse of glutamate, in the presence of various concentrations of amiloride, resulted in a dose-dependent protection from neurotoxicity (EC50 300 microM, complete protection 1 mM). In voltage-clamped cortical and cerebellar neurons of neonatal rats in primary culture, 100 microM amiloride diminished (by about 25%) glutamate- and/or NMDA-evoked cationic currents, recorded in the whole-cell mode. About 80% of the NMDA-(20 microM) stimulated current was inhibited by 700 microM amiloride. The inhibitory effect of amiloride was not voltage-dependent. In outside-out membrane patches, excised from granule cells and held at -50 mV, 100 microM amiloride changed the NMDA-elicited single channel activity into a fast flickering between the open and closed states. The noise analysis of the data revealed that, although resembling the Mg2(+)-induced flickering, the amiloride-induced channel block was more similar to the effects described for the action of local anaesthetics on the nicotinic cholinergic channel. The pharmacological relevance of this action of amiloride requires further characterization; the data point out the necessity of a cautious use of amiloride in studying neuronal function.


Asunto(s)
Amilorida/farmacología , Canales de Calcio/fisiología , Glutamatos/farmacología , Neuronas/fisiología , Animales , Animales Recién Nacidos , Calcio/metabolismo , Canales de Calcio/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Cerebelo/citología , Cerebelo/fisiología , Potenciales de la Membrana/efectos de los fármacos , N-Metilaspartato/farmacología , Neuronas/citología , Neuronas/efectos de los fármacos , Ratas
10.
Neuropharmacology ; 28(5): 453-7, 1989 May.
Artículo en Inglés | MEDLINE | ID: mdl-2471112

RESUMEN

The action of kynurenic acid on currents elicited by the activation of amino acid receptors was investigated in primary cultures of cortical neurons prepared from neonatal rats. Kynurenic acid was tested on currents elicited by both N-methyl-D-aspartic acid (NMDA) and kainate, using patch-clamp recording techniques in "outside-out" and "whole-cell" configurations. The inhibition by kynurenic acid was compared with that elicited by amino-phosphono-valeric acid (APV). Whole-cell currents, elicited by increasing doses of NMDA, were antagonized competitively by APV and non-competitively by kynurenic acid (ID50 70 microM); in contrast, kynurenic acid inhibited competitively the whole-cell currents elicited by kainic acid (ID50 500 microM). The non-competitive inhibition by kynurenic acid of the whole cell currents elicited by NMDA was antagonized competitively by glycine, a specific positive allosteric modulator of NMDA receptors; on the other hand glycine failed to change the inhibition by APV of the NMDA-elicited responses. Thus, kynurenic acid inhibits NMDA receptors allosterically (non-competitively) and kainic acid receptors isosterically (competitively).


Asunto(s)
Ácido Quinurénico/farmacología , Contracción Miocárdica/efectos de los fármacos , Receptores de Neurotransmisores/efectos de los fármacos , Animales , Animales Recién Nacidos , Células Cultivadas , Electrofisiología , Técnicas In Vitro , Canales Iónicos/efectos de los fármacos , Ratas , Ratas Endogámicas , Receptores de Ácido Kaínico , Receptores de N-Metil-D-Aspartato , Receptores de Neurotransmisores/metabolismo , Sinapsis/efectos de los fármacos
11.
Neuropharmacology ; 29(10): 969-72, 1990 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-2175017

RESUMEN

In primary cultures of cerebellar granule cells, D,L baclofen (p-chlorophenyl-GABA) inhibited approximately 50% of the calcium-45 influx induced with cell depolarization. The half maximal effective concentration for baclofen was 4 nM. Basal calcium influx was not influenced by baclofen thus suggesting that its inhibitory action could be exerted via a voltage dependent calcium channel (VDCC). Whole-cell recordings by patch-clamp technique showed a calcium current that appeared to be similar to the reported L-type VDCC. Nanomolar concentrations of baclofen also inhibited this calcium current by about 60%. However, in order for baclofen to be active, it needed to be placed into the incubation buffer at least five minutes before patching a cell raising the possibility that baclofen may be acting to inhibit the VDCC via a second messenger system.


Asunto(s)
Baclofeno/farmacología , Canales de Calcio/fisiología , Cerebelo/fisiología , Animales , Transporte Biológico/efectos de los fármacos , Calcio/metabolismo , Canales de Calcio/efectos de los fármacos , Células Cultivadas , Cerebelo/citología , Cerebelo/efectos de los fármacos , Potenciales de la Membrana/efectos de los fármacos
12.
Neuroscience ; 79(3): 671-81, 1997 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-9219932

RESUMEN

Spontaneous postsynaptic currents were investigated in neurons of the caudal portion of the dorsal motor nucleus of the vagus using the patch-clamp technique to study the effect of neuronal nicotinic acetylcholine receptor activation on synaptic transmission. In voltage-clamped neurons, bath application of nicotine (1-30 microM) elicited a concentration-dependent increase in the frequency of the spontaneous synaptic currents. The effect was also observed with application of the nicotinic receptor agonists epibatidine (10 nM) and cytisine (10 microM). Mecamylamine (20 microM) and curare (50 microM), two nicotinic receptor antagonists, both decreased the effect of 3 microM nicotine on the frequency of the spontaneous postsynaptic currents. This effect of 3 microM nicotine was also blocked by 20 microM bicuculline, a competitive antagonist of the GABA(A) receptor; in contrast, it was not affected by 1 mM kynurenic acid, an antagonist of the ionotropic glutamate receptor. In the presence of 1 microM tetrodotoxin, 3 microM nicotine was unable to affect the synaptic activity. Our findings suggest the existence of nicotinic receptors on GABAergic axons projecting to the vagal motoneurons. Because the effect is completely abolished by 1 microM tetrodotoxin, the nicotinic receptors are not localized on the presynaptic nerve terminal and their action on the GABA release requires the propagation of an action potential from their location to the synaptic terminal. This effect of nicotinic receptor activation on spontaneous GABA release in the dorsal motor nucleus of the vagus may have an important role in the regulation of gastrointestinal motility.


Asunto(s)
Tronco Encefálico/efectos de los fármacos , Nicotina/farmacología , Receptores Nicotínicos/efectos de los fármacos , Sistema Nervioso Simpático/efectos de los fármacos , Transmisión Sináptica/efectos de los fármacos , Ácido gamma-Aminobutírico/metabolismo , Acetilcolina/farmacología , Animales , Técnicas de Placa-Clamp , Ratas , Ratas Sprague-Dawley
13.
Growth Horm IGF Res ; 14(3): 226-34, 2004 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-15125884

RESUMEN

The aim of this study was to assess the in vivo efficacy of monoPEGylated GRF(1-29)NH(2) having one PEG(5000) chains attached to either lysine 12 or 21 as compared to the GRF(1-29)NH(2) in rats and pigs. This analogue termed GRF-1PEG(5000) was tested after a single intravenous administration in rats and after a single intravenous or subcutaneous injection in pigs. After 1 h administration, GH concentrations returned to values close to controls in the group of rats injected with GRF(1-29)NH(2). In animals injected with the same dose of GRF-1PEG(5000), the AUC values corresponding to the whole period 0.5-48 h and particularly to the 0.5-8 h period were higher than in the placebo or in the GRF(1-29)NH(2) groups. Interestingly, two additional peaks were observed at about 6 and 8 h following administration. An increase in the response of the endogenous GH peaks was also observed in pigs administered GRF-1PEG(5000) by intravenous route. When GRF-1PEG(5000) was administered subcutaneously to pigs, a significant increase, as compared to placebo and GRF(1-29)NH(2,) in both GH and IGF-I levels was observed. This new analogue might find therapeutic application in paediatric growth hormone deficiency or in aging.


Asunto(s)
Hormona Liberadora de Hormona del Crecimiento/análogos & derivados , Polietilenglicoles/química , Sermorelina/análogos & derivados , Sermorelina/farmacología , Animales , Hormona del Crecimiento/sangre , Hormona del Crecimiento/metabolismo , Hormona Liberadora de Hormona del Crecimiento/sangre , Hormona Liberadora de Hormona del Crecimiento/metabolismo , Humanos , Inyecciones Intravenosas , Inyecciones Subcutáneas , Factor I del Crecimiento Similar a la Insulina/análisis , Factor I del Crecimiento Similar a la Insulina/metabolismo , Masculino , Ratas , Ratas Sprague-Dawley , Sermorelina/administración & dosificación , Porcinos
14.
Neurosci Lett ; 84(3): 351-5, 1988 Feb 03.
Artículo en Inglés | MEDLINE | ID: mdl-2451195

RESUMEN

Glutamate activates high (40-50 pS) and low (5-15 pS) conductance cationic channels in outside-out patches excised from cultured cortical and cerebellar granule neurons of neonatal rats. In these neurons, the excitatory amino acid N-methyl-D-aspartic acid (NMDA) activates mainly high conductance channels. Phencyclidine (PCP) at 2 microM selectively reduces the number of NMDA-activated channel openings, at 20 microM it reduces the channel open-time. Glycine increases the opening frequency of high conductance NMDA-activated channels. This action is counteracted by PCP. This inhibition by PCP can be eliminated by reversing the polarity of the membrane patch. However, the effect of glycine is voltage independent. These results imply different sites of action for these two modulators.


Asunto(s)
Glicina/farmacología , Canales Iónicos/fisiología , Neuronas/fisiología , Fenciclidina/farmacología , Animales , Animales Recién Nacidos , Ácido Aspártico/análogos & derivados , Ácido Aspártico/farmacología , Células Cultivadas , Cerebelo/fisiología , Corteza Cerebral/fisiología , Conductividad Eléctrica , Canales Iónicos/efectos de los fármacos , N-Metilaspartato , Neuronas/efectos de los fármacos , Ratas
15.
J Pain Symptom Manage ; 9(8): 515-9, 1994 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-7531736

RESUMEN

Constipation is a frequent and distressing complication in patients with advanced cancer. However, very few studies have reviewed the assessment and management of these patients. The purpose of this study was to review the documentation and assessment and diagnosis of constipation in patients admitted to a Palliative Care Unit, and the correlation between those findings and radiological evidence of stool in the colon. The records of 122 consecutive patients admitted to the Palliative Care Unit, Edmonton General Hospital were reviewed in order to assess the physician's and the nurse's record of symptoms, physical findings, and diagnosis and treatment of constipation. All patients also underwent a flat abdominal radiograph that scored for the presence of stool in the colon (0 = no stool; and 12 = stool occupying all the lumen of the four quadrants of the colon). The radiograph was scored blindly by two different physicians. Of 103 evaluable patients, a rectal exam was reported only in 42. Correlation between the assessment by the two physicians' radiograph score was high (0.78, P nd nurses' diagnosis of constipation, the presence of laxative treatment, the number of days since the last bowel movement, and the source of the admission (hospital vs home) were not associated with higher radiological scores for constipation. Assessment is insufficient in this population at high risk for severe constipation. Radiological examination may be necessary for adequate diagnosis in some patients. More research is needed in this area.


Asunto(s)
Estreñimiento/diagnóstico , Estreñimiento/etiología , Neoplasias/complicaciones , Cuidados Paliativos , Cuidado Terminal , Anciano , Colon/diagnóstico por imagen , Estreñimiento/terapia , Femenino , Unidades Hospitalarias , Humanos , Masculino , Persona de Mediana Edad , Radiografía , Estudios Retrospectivos
16.
J Palliat Care ; 12(1): 38-41, 1996.
Artículo en Inglés | MEDLINE | ID: mdl-8857246

RESUMEN

Treatment of patients with advanced-stage hematological malignancies (HM) includes frequent transfusions. Given present limited hospital budgets, administrative pressure is increasing on hematology services to limit the cost of these transfusions. An expert multidisciplinary panel involved in hematology formed a working party to draw up a series of proposals, including definitions of advanced stage disease and the indications for platelet transfusion. Their proposals included: (a) Platelet transfusions are indicated for the treatment of bleeding caused by low platelet counts; (b) Patients should receive full information, including the basic criteria for platelet transfusion; (c) Doctors should be trained to assess whether or not platelet transfusions are urgently required; and (d) The practice of home transfusions should be encouraged.


Asunto(s)
Enfermedades de la Médula Ósea/terapia , Leucemia/terapia , Linfoma/terapia , Transfusión de Plaquetas , Enfermedades de la Médula Ósea/inducido químicamente , Toma de Decisiones , Humanos , Paris , Transfusión de Plaquetas/economía , Calidad de Vida
17.
Eur J Drug Metab Pharmacokinet ; 23(2): 230-8, 1998.
Artículo en Inglés | MEDLINE | ID: mdl-9725487

RESUMEN

Pharmacokinetics of [14C]-ITF-296 and its metabolites, ITF-1124 and ITF-1577, were studied in rats after a single intravenous (2.5 mg/kg) and oral (10 mg/kg) administration. Radioactivity was measured by LSC while unchanged drug and its metabolites in plasma were assayed by an HPLC-UV method. The absorption of [14C]-ITF-296 after oral administration is practically complete. Elimination of radioactivity occurs mainly in urine (higher than 80%) and the recovery of the dose (higher than 95%) takes place up to 96 h after both treatments. Both by i.v. and p.o. route the results show that the radioactivity is largely excreted in the bile and reabsorbed in the intestine. The tissue distribution study indicates that there is no accumulation or localization of radioactivity in the major organs or blood and no radioactivity levels are found 96 h after either treatment. In addition, whole body autoradiography confirms the tissue distribution pattern, showing no differences between albino and pigmented rats.


Asunto(s)
Nitratos/farmacocinética , Oxazinas/farmacocinética , Administración Oral , Animales , Autorradiografía , Benzoxazinas , Bilis/metabolismo , Radioisótopos de Carbono , Inyecciones Intravenosas , Masculino , Nitratos/sangre , Óxido Nítrico/metabolismo , Oxazinas/sangre , Radiofármacos/farmacocinética , Ratas , Ratas Sprague-Dawley , Distribución Tisular
18.
Eur J Drug Metab Pharmacokinet ; 23(2): 223-9, 1998.
Artículo en Inglés | MEDLINE | ID: mdl-9725486

RESUMEN

The absorption, excretion and tissue distribution of radioactivity after repeated oral equimolar doses of 14C-valproic acid sodium salt (NaVP) or 14C-valproic acid pivaloyl oxymethyl ester (PEV) was investigated in male rats treated once a day for 14 consecutive days. The 14th day plasma time-course of radioactivity after PEV administrations was characterised by a slow absorption rate with a delayed peak (tmax 2 h, Cmax 7.52 +/- 1.35 microg eq./ml), followed by a plateau lasting up to 8 h. After NaVP treatment, the main peak of radioactivity was observed 0.5 h after administration (Cmax 8.30 +/- 1.26 microg eq./ml) followed by a secondary peak due to biliary enterohepatic recycling. Starting from 4 h onwards, radioactivity levels after PEV treatment were higher than those after NaVP (AUCtau = 113.3 h.microg eq./ml after PEV vs 71.9 h.microg eq./ml after NaVP), but concentrations declined with similar terminal half-lives (52.8 h for PEV and 49.7 h for NaVP). Radioactivity recovered (0-432 h interval) in urine accounted for 79.3% (PEV) and 56.1% (NaVP) while, in faeces accounted for 9.1% (PEV) and 26.1% (NaVP) of total administered dose (14 days). The difference is attributable to a higher excretion of radioactivity in the bile for NaVP. The missing fraction in the total radioactivity balance is probably excreted in expired air, as observed in single dose studies. Radioactivity excreted in bile (0-8 h interval of the last 14th day) accounted for 5.1% (NaVP) and 0.23% (PEV) of the total administered dose (14 days). A possible explanation of this difference may be a different metabolism pattern for the two compounds. The negligible biliary excretion observed after PEV administration is probably due to an inhibition of the glucuronation of valproic acid (or other metabolites) caused by the pivalic acid. Due to the presence of the enterohepatic recycle, the radioactivity levels in intestine, 0.5 and 2 h after administration, were higher after NaVP administration. According to higher plasma levels, the radioactivity concentrations in liver, kidneys and some fat tissues were found to be slightly higher after PEV administration. At 120 h after the last treatment of both compounds, relevant tissue concentrations were observed in mesenteric lymphnodes, perirenal and brown fat. The tissue-plasma radio activity ratio appeared quite similar for the two compounds.


Asunto(s)
Ácido Valproico/análogos & derivados , Ácido Valproico/farmacocinética , Administración Oral , Animales , Radioisótopos de Carbono/análisis , Masculino , Radiofármacos/farmacocinética , Ratas , Ratas Sprague-Dawley , Distribución Tisular , Ácido Valproico/sangre
19.
Eur J Drug Metab Pharmacokinet ; 23(2): 239-50, 1998.
Artículo en Inglés | MEDLINE | ID: mdl-9725488

RESUMEN

Pharmacokinetics of [14C]-ITF-296 and its metabolites, ITF-1124 and ITF-1577, were studied in dogs and monkeys after a single intravenous (2.5 mg/kg) and oral (10 mg/kg) administration. Radioactivity was measured by LSC while unchanged drug and its metabolites in plasma were assayed by an HPLC-UV method. The absorption of [14C]-ITF-296 after oral administration is practically complete both in dogs and in monkeys. The determination of unchanged drug and its metabolites shows quite a similar profile in dogs and monkeys for ITF-296 and ITF-1124 and a different time-course for ITF-1577. Elimination of radioactivity occurs mainly in urine (namely 70-80%) for both species and the recovery of the dose (higher than 90%) takes place up to 96 h after both treatments.


Asunto(s)
Nitratos/farmacocinética , Oxazinas/farmacocinética , Absorción , Administración Oral , Animales , Benzoxazinas , Radioisótopos de Carbono , Perros , Inyecciones Intravenosas , Isquemia/prevención & control , Macaca fascicularis , Masculino , Nitratos/sangre , Oxazinas/sangre
20.
Minerva Chir ; 49(10 Suppl 1): 69-74, 1994 Oct.
Artículo en Italiano | MEDLINE | ID: mdl-7700558

RESUMEN

We want to present our experience performed at the Institute of Radiology of Turin: 98 TIPS in 97 patients (in 1 patient, twice). METHODS. From March 1992, 97 cirrhotic patients (18 Child A, 48 Child B, 31 Child C) underwent the TIPS procedure for portal hypertension. The indications were digestive hemorrhage in 81 patients (20 of which performed in emergency for acute bleeding), intractable ascites in 13 patients and bleeding prevention in 3 patients. RESULTS. Immediate technical success was obtained in 95/98 cases (96.9%). Patients were monitored by US-Doppler at 24 hours, 2 months and every 6 months and by esophagogastroscopy at 2 and 6 months. Major clinical complications included CID (2 cases), hepatic failure (3 cases), renal insufficiency (2 cases), heart failure (1 case), recurrent bleeding (6 cases) and encephalopathy (15 cases). We had 5 early occlusion and 17 late stenosis of the shunt; 21 patients in this group were successfully treated either by PTA or restenting; one patient underwent a surgical shunt. Mortality rate follow-up was 0/17 among Child A patients, 7/48 (14.5%) among Child B patients and 12/29 (41.3%) among Child C patients. CONCLUSIONS. TIPS is a safe and valuable method for the treatment of portal hypertension. Though shunt stenosis may occur with a certain frequency (22/95, 23.1% in our study), a second intervention is usually effective in reducing gastro-oesophageal varices and ascites.


Asunto(s)
Derivación Portosistémica Quirúrgica/métodos , Adulto , Anciano , Anciano de 80 o más Años , Várices Esofágicas y Gástricas/diagnóstico por imagen , Várices Esofágicas y Gástricas/cirugía , Femenino , Estudios de Seguimiento , Hemorragia Gastrointestinal/diagnóstico por imagen , Hemorragia Gastrointestinal/cirugía , Humanos , Hipertensión Portal/diagnóstico por imagen , Hipertensión Portal/cirugía , Venas Yugulares , Cirrosis Hepática/diagnóstico por imagen , Cirrosis Hepática/cirugía , Masculino , Persona de Mediana Edad , Derivación Portosistémica Quirúrgica/instrumentación , Radiografía , Stents
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