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1.
J Pediatr Gastroenterol Nutr ; 78(3): 704-710, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38314914

RESUMEN

There is a scarcity of nutritional screening tools for use in infants (<1 year). The infant Nutrition Early Warning Score (iNEWS) has been developed to identify infants who need further dietetic review. We introduced the iNEWS into clinical practice and evaluated its performance in Scotland, Belgium, Athens and Bulgaria. Of the 352 infants screened, 72 (20%) were placed in the high iNEWS category, and of these, 70 (97%) were reviewed by a hospital dietitian. iNEWS produced a true positive rate of 80% which increased to 96% after accounting for anticipated misclassified cases due to prematurity. In Belgium, false positive screens had a shorter length of stay (p = 0.014). Otherwise, misclassification was not related to a specific iNEWS component. This study corroborates previous research, underscoring the validity of iNEWS as a dietetic referral tool and demonstrating that it can be integrated into "real-world" clinical practice across international settings with diverse healthcare resources.


Asunto(s)
Puntuación de Alerta Temprana , Desnutrición , Lactante , Humanos , Estado Nutricional , Evaluación Nutricional , Opinión Pública , Desnutrición/diagnóstico , Europa (Continente)
2.
J Surg Res ; 186(1): 119-25, 2014 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-24157266

RESUMEN

BACKGROUND: Bipolar electrosurgical tissue welding uses forceps-like electrodes for grasping the tissues and delivering high-frequency electric current (HFEC) to produce local heat, desiccation, and protein denaturation, resulting in the fusion of the contacting tissues. Although in this technique no electric current is flowing through the whole body to cause electric injury, depending on the frequency of applied energy, it may produce local excitation of intramural nerves, which can propagate beyond the surgical site potentially causing harmful effects. MATERIALS AND METHODS: The effects of varying frequency of HFEC on tissue excitability in bipolar electrosurgical modality were studied in vitro using electric field stimulation (EFS) method on multicellular smooth muscle strips of rat vas deferens. Contractile response to 5-s-long sine wave EFS train was taken as the measure of excitation of intramural nerves. RESULTS: EFS-induced contraction consisted of phasic and tonic components. The amplitude of both components decreased with increasing frequency, with tonic component disappearing at about 10 kHz and phasic component at about 50 kHz. Because components of EFS-induced contraction depend on different neurotransmitters, this indicates that various neurotransmitter systems are characterized by distinct frequency dependence, but above 50 kHz they all become inactivated. Bipolar electrosurgical sealing of porcine gut showed no difference in the structure of seal area at HFEC of 67 and 533 kHz. CONCLUSIONS: EFS frequency of 50 kHz represents the upper limit for excitation. HFEC above 50 kHz is safe to use for bipolar electrosurgical tissue welding without concerns of excitation propagating beyond the surgical site.


Asunto(s)
Electrocirugia/métodos , Acoplamiento Excitación-Contracción , Músculo Liso/fisiología , Animales , Estimulación Eléctrica , Masculino , Ratas , Ratas Wistar , Conducto Deferente/fisiología
3.
Eur J Pharmacol ; 860: 172529, 2019 Oct 05.
Artículo en Inglés | MEDLINE | ID: mdl-31299187

RESUMEN

Parasympathetic regulation of urinary bladder contractions primarily involves acetylcholine release and activation of detrusor smooth muscle (DSM) muscarinic acetylcholine (mACh) receptors. Co-release of ATP and activation of DSM purinergic P2X1-receptors may participate as well in some species. Both types of neuromuscular transmission (NMT) are impaired in diabetes, however, which factors may contribute to such impairment remains poorly understood. Here by using rats with streptozotocin(STZ)-induced type I diabetes (8th week after induction) we show that contribution of atropine-sensitive m-cholinergic component to the contractions of urothelium-denuded DSM strips evoked by electric field stimulation (EFS) greatly increased when diabetic bladders presented overt signs of accompanying cystitis. Modeling of hemorrhagic cystitis alone in control rats by cyclophosphamide injection only modestly increased m-cholinergic component of EFS-contractions. However, exposure of DSM strips from control animals to acetylcholinesterase (AChE) inhibitor, neostigmine (1-10 µM) largely reproduced alterations in EFS contractions observed in diabetic DSM complicated by cystitis. Ellman's assay revealed statistically significant 31% decrease of AChE activities in diabetic vs. control DSM. Changes in purinergic contractility of diabetic DSM were consistent with altered P2X1-receptor desensitization and re-sensitization. They could be mimicked by pharmacological inhibition of ATP-degrading ecto-ATPases with ARL 67156 (50 µM), pointing to compromised extracellular ATP clearance as underlying reason. We conclude that decreased AChE activities associated with diabetes and likely cystitis provide complementary factor to the described in literature altered expression of mACh receptor subtypes linked to diabetes as well as to cystitis to produce dramatic modification of cholinergic NMT.


Asunto(s)
Acetilcolina/metabolismo , Cistitis/complicaciones , Diabetes Mellitus Tipo 1/enzimología , Diabetes Mellitus Tipo 1/fisiopatología , Contracción Muscular , Neurotransmisores/metabolismo , Vejiga Urinaria/fisiopatología , Acetilcolinesterasa/genética , Acetilcolinesterasa/metabolismo , Adenosina Trifosfato/metabolismo , Animales , Diabetes Mellitus Tipo 1/complicaciones , Diabetes Mellitus Tipo 1/metabolismo , Modelos Animales de Enfermedad , Espacio Extracelular/metabolismo , Regulación Enzimológica de la Expresión Génica , Masculino , Ratas , Ratas Wistar
4.
J Gerontol A Biol Sci Med Sci ; 62(3): 264-70, 2007 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-17389723

RESUMEN

The role of aging on contraction or relaxation through muscarinic or alpha-adrenergic receptors, respectively, was studied in isolated rat jejunum. Furthermore, the influence of extracellular calcium was analyzed, through functional and radioligand binding assays. The rank order of potency for selective muscarinic antagonists for M(1), M(2), and M(3) receptor subtypes, measured from affinity (pA(2)) values, was p-fluorohexahydrosiladifenidol (pFHHSiD) (M(3)) > pirenzepine (M(1)) > methoctramine (M(2)), indicating a predominance of M(3) subtype. This order was unchanged with age. Contractions by muscarinic agonist methacholine (MCh) were diminished in aged rats, resulting in lower apparent affinity (pD(2)) values, compared with adult controls. A larger decrease of MCh contractions occurred in aged rats after Ca(2+) withdrawal or after the calcium channel blocker isradipine. Changes were not detected for relaxation by adrenergic agonists. In conclusion, aging caused a decrease of MCh potency, which is probably related to the reduction of calcium sensitivity in jejunum.


Asunto(s)
Envejecimiento/fisiología , Señalización del Calcio/fisiología , Yeyuno/fisiología , Peristaltismo/fisiología , Receptores Adrenérgicos alfa/fisiología , Receptores Muscarínicos/fisiología , Agonistas Adrenérgicos/farmacología , Animales , Bloqueadores de los Canales de Calcio/farmacología , Canales de Calcio Tipo L/efectos de los fármacos , Diaminas/farmacología , Isradipino/farmacología , Masculino , Cloruro de Metacolina/farmacología , Agonistas Muscarínicos/farmacología , Antagonistas Muscarínicos/farmacología , Piperidinas/farmacología , Pirenzepina/farmacología , Ratas , Ratas Wistar , Receptor Muscarínico M1/antagonistas & inhibidores , Receptor Muscarínico M2/antagonistas & inhibidores , Receptor Muscarínico M3/antagonistas & inhibidores , Receptores Muscarínicos/efectos de los fármacos
5.
Exp Gerontol ; 41(1): 55-62, 2006 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-16343836

RESUMEN

In this study, we investigated the effect of aging on intracellular Ca2+ stores, as sarcoendoplasmic reticulum (SR) and mitochondria, and the influence of these compartments on contraction of rat colon smooth muscle [Bitar, K.N., 2003. Aging and neural control of the GI tract V. Aging and gastrointestinal smooth muscle: from signal transduction to contractile proteins. Am. J. Physiol. Gastrointest. Liver. Physiol. 284(1), G1-G7; Marijic, J., Li, Q.X., Song, M., Nishimaru, K., Stefani, E., Toro, L., 2001. Decreased expression of voltage-and Ca2+-activated K+ channels in coronary smooth muscle during aging. Circ. Res. 88, 210-234; Rubio, C., Moreno, A., Briones, A. Ivorra, M.D., D'Ocon, P., Vila, E., 2002. Alterations by age of calcium handling in rat resistance arteries. J. Cardiovasc. Pharmacol. 40(6), 832-840]. Calcium stores and contraction were evaluated by simultaneous measurements of fluorescence and tension in smooth muscle strips loaded with fura-2. Results showed that activation of muscarinic receptors by methylcholine (MCh, 10 microM), induced a greater contraction in aged rats than in adult animals. The inhibition of Ca2+ ATPase by thapsigargin (TG, 1 microM) did not prevent the refilling of SR either in adult or aged rats. MCh, in the presence of TG, induced an increase in transient fluorescence, indicating a release of Ca2+ from TG-insensitive compartment. The mitochondrial uncoupler, FCCP (5 microM), caused a greater increase in intracellular Ca2+ and tension in aged rats, indicating that mitochondria may accumulate more Ca2+ during aging. The present results show that changes in intracellular Ca2+ stores, such as mitochondria and SR, affect contraction and may cause dysfunctions during aging that could culminate in severe alterations of Ca2+ homeostasis and cell damage.


Asunto(s)
Envejecimiento/metabolismo , Calcio/metabolismo , Colon/metabolismo , Contracción Muscular/fisiología , Músculo Liso/metabolismo , Envejecimiento/fisiología , Animales , ATPasas Transportadoras de Calcio/antagonistas & inhibidores , ATPasas Transportadoras de Calcio/fisiología , Carbonil Cianuro p-Trifluorometoxifenil Hidrazona/farmacología , Colina/análogos & derivados , Colina/farmacología , Colon/efectos de los fármacos , Colon/fisiología , Interacciones Farmacológicas , Inhibidores Enzimáticos/farmacología , Femenino , Mitocondrias Musculares/metabolismo , Contracción Muscular/efectos de los fármacos , Músculo Liso/efectos de los fármacos , Músculo Liso/fisiología , Ratas , Ratas Wistar , Retículo Sarcoplasmático/metabolismo , Tapsigargina/farmacología , Técnicas de Cultivo de Tejidos , Desacopladores/farmacología
6.
Eur J Pharmacol ; 470(1-2): 37-43, 2003 May 30.
Artículo en Inglés | MEDLINE | ID: mdl-12787829

RESUMEN

The effect of nantenine, an aporphine alkaloid isolated from Ocotea macrophylla H.B.K., was studied on contractions and Ca(2+) translocation induced by noradrenaline, Ca(2+), or K(+) in the isolated rat vas deferens from reserpinized animals. Concentration-response curves of calcium chloride (CaCl(2)) were performed in the vas deferens, in a Ca(2+)-free nutrient solution, using potassium chloride (KCl, 80 mM) as a depolarizing agent. In these conditions, nantenine (2.35 x 10(-4) and 4.7 x 10(-4) M) significantly reduced the maximum contractions (E(max)) of Ca(2+) (IC(50)=2.6 x 10(-4) M) and noradrenaline (IC(50)=2.9 x 10(-4) M). The contractile responses were totally recovered after the withdrawal of nantenine. In addition, experiments performed to measure simultaneously the contraction and the increase of intracellular Ca(2+) induced by noradrenaline (10(-5) M) or KCl (80 mM) showed that nantenine (2.35 x 10(-4) and 4.7 x 10(-4) M) significantly decreased both effects. The results suggest that a reversible block of Ca(2+) entry could be involved on the non-competitive-like antagonism of nantenine in rat vas deferens.


Asunto(s)
Aporfinas/farmacología , Calcio/antagonistas & inhibidores , Contracción Muscular/efectos de los fármacos , Norepinefrina/farmacología , Cloruro de Potasio/farmacología , Animales , Calcio/fisiología , Cloruro de Calcio/farmacología , Relación Dosis-Respuesta a Droga , Masculino , Contracción Muscular/fisiología , Ocotea , Extractos Vegetales/aislamiento & purificación , Extractos Vegetales/farmacología , Ratas , Conducto Deferente/efectos de los fármacos , Conducto Deferente/fisiología
7.
Comp Biochem Physiol A Mol Integr Physiol ; 148(3): 599-610, 2007 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-17869562

RESUMEN

The rate of oxygen consumption (V(O2)), embryo mass, distribution and mass of the chorioallantoic membrane (CAM), heart rate (HR), heart mass, and amnion rhythmic contractions (ARC) were studied in eggs of the European pond turtle (Emys orbicularis) incubated at 28 degrees C for 62.5+/-0.3 days. The V(O2) rapidly increased beginning from incubation day 19 (D19) to a maximum on D50 and then decreased until pipping. The rapid V(O2) rise was correlated with an increase in the CAM surface and mass, heart mass, and ARC amplitude, whereas the functional parameters such as HR and ARC frequency remained unchanged. The drop in V(O2) before pipping was accompanied by a decrease in HR, while the heart and CAM masses were almost constant. In the cases of short-term temperature deviations of +/-3 degrees C from 28 degrees C, changes in (O2) were significant until D50 and nonsignificant after that, the changes in ARC frequency and HR being significant at all stages studied. Thus, the developmental V(O2) changes were contributed mainly by the slow morphogenetic processes during D19-D50, whereas changes in functional parameters began to play a role at later stages. The response to temperature fluctuations was mediated by a rapid change in functional parameters at all these stages.


Asunto(s)
Sistema Cardiovascular/metabolismo , Membranas Extraembrionarias/metabolismo , Consumo de Oxígeno , Tortugas/metabolismo , Alantoides/embriología , Alantoides/metabolismo , Amnios/embriología , Amnios/metabolismo , Animales , Sistema Cardiovascular/embriología , Membrana Corioalantoides/embriología , Membrana Corioalantoides/metabolismo , Embrión no Mamífero/metabolismo , Desarrollo Embrionario , Membranas Extraembrionarias/embriología , Corazón/embriología , Frecuencia Cardíaca , Modelos Biológicos , Morfogénesis , Tamaño de los Órganos , Temperatura , Tortugas/embriología
8.
Pflugers Arch ; 446(3): 380-6, 2003 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-12684789

RESUMEN

Voltage-gated components of the outward current in single smooth muscle cells isolated from the epididymal part of the rat vas deferens were studied using amphotericin B perforated patch-clamp techniques. The complex kinetics of the net outward current elicited by positive voltage steps from -80 mV to +40 mV suggested the presence of several components. Bath application of 200 nM charybdotoxin, a potent blocker of large-conductance, Ca(2+)-dependent K(+) channels (BK(Ca)), reduced the current amplitude significantly. When BK(Ca) channels were suppressed, fast-inactivating (I(K,f)) and delayed rectifying (I(K,dr)) components of the outward current were identified. I(K,f) was characterized by fast kinetics of current decay, negative steady-state activation and inactivation dependencies and sensitivity to 4-aminopyridine with an apparent K(d) of 0.32 mM, properties similar to those of the A-type K(+) current. In contrast, I(K,dr) activated and inactivated at more positive potentials. The time constant of activation of I(K,dr) was voltage dependent with an e-fold decrease per 21 mV depolarization. I(K,dr) was inhibited by clofilium, a blocker of voltage-gated K(+) channels, with an IC(50) of 12 micro M and was not blocked by 5 mM 4-aminopyridine. The possible significance of the voltage-gated currents is discussed.


Asunto(s)
Miocitos del Músculo Liso/metabolismo , Canales de Potasio con Entrada de Voltaje/fisiología , Conducto Deferente/metabolismo , 4-Aminopiridina/administración & dosificación , 4-Aminopiridina/farmacología , Animales , Fenómenos Biofísicos , Biofisica , Caribdotoxina/farmacología , Canales de Potasio de Tipo Rectificador Tardío , Relación Dosis-Respuesta a Droga , Conductividad Eléctrica , Canales de Potasio de Gran Conductancia Activados por el Calcio , Masculino , Modelos Biológicos , Miocitos del Músculo Liso/citología , Bloqueadores de los Canales de Potasio/farmacología , Canales de Potasio/fisiología , Canales de Potasio Calcio-Activados/antagonistas & inhibidores , Canales de Potasio con Entrada de Voltaje/efectos de los fármacos , Ratas , Ratas Wistar , Tetraetilamonio/farmacología , Conducto Deferente/citología
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