Early in vivo detection of denervation-induced atrophy by luminescence transient nanothermometry.

Denervation induces skeletal muscle atrophy due to the loss of control and feedback with the nervous system. Unfortunately, muscle atrophy only becomes evident days after the denervation event when it could be irreversible. Alternative diagnosis tools for early detection of denervation-induced muscle atrophy are, thus, required. In this work, we demonstrate how the combination of transient thermometry, a technique already used for early diagnosis of tumors, and infrared-emitting nanothermometers makes possible the in vivo detection of the onset of muscle atrophy at short (<1 day) times after a denervation event. The physiological reasons behind these experimental results have been explored by performing three dimensional numerical simulations based on the Pennes' bioheat equation. It is concluded that the alterations in muscle thermal dynamics at the onset of muscle atrophy are consequence of the skin perfusion increment caused by the alteration of peripheral nervous autonomous system. This work demonstrates the potential of infrared luminescence thermometry for early detection of diseases of the nervous system opening the venue toward the development of new diagnosis tools.

Time-dependent dual effect of NLRP3 inflammasome in brain ischaemia.

BACKGROUND: Inflammasomes are cytosolic multiprotein complexes which, upon assembly, activate the maturation and secretion of the inflammatory cytokines IL-1ß and IL-18. However, participation of the NLRP3 inflammasome in ischaemic stroke remains controversial. Our aims were to determine the role of NLRP3 in brain ischaemia, and explore the mechanism involved in the potential protective effect of the neurovascular unit. METHODS: WT and NLRP3 knock-out mice were subjected to ischaemia by middle cerebral artery occlusion (60 min) with or without treatment with MCC950 at different time points post-stroke. Brain injury was measured histologically with 2,3,5-triphenyltetrazolium chloride (TTC) staining. RESULTS: We identified a time-dependent dual effect of NLRP3. While neither the pre-treatment with MCC950 nor the genetic approach (NLRP3 KO) proved to be neuroprotective, post-reperfusion treatment with MCC950 significantly reduced the infarct volume in a dose-dependent manner. Importantly, MCC950 improved the neuro-motor function and reduced the expression of different pro-inflammatory cytokines (IL-1ß and TNF-α), NLRP3 inflammasome components (NLRP3 and pro-caspase-1), protease expression (MMP9), and endothelial adhesion molecules (ICAM and VCAM). We observed a marked protection of the blood-brain barrier (BBB), which was also reflected in the recovery of the tight junction proteins (ZO-1 and Claudin-5). Additionally, MCC950 produced a reduction of the CCL2 chemokine in blood serum and in brain tissue, which lead to a reduction in the immune cell infiltration. CONCLUSIONS: These findings suggest that post-reperfusion NLRP3 inhibition may be an effective acute therapy for protecting the blood-brain barrier in cerebral ischaemia with potential clinical translation.

Uso de Solución Hipertónica en pacientes con insuficiencia cardiaca aguda como terapia adyuvante a altas dosis de diuréticos / Use of Hypertonic Solution in patients with acute heart failure as adjunctive therapy to high-dose diuretics

Resumen La insuficiencia cardíaca aguda descompensada (ICAD) es una causa común de hospitalización, con repercusiones significativas en los sistemas de salud. El manejo agudo se basa en la reducción de la volemia con diuréticos de asa, sin embargo, un porcentaje de pacientes presenta resistencia o no logra la respuesta clínica esperada con este tratamiento. Una de las medidas que ha comprobado ser efectiva en este contexto, es el uso de solución salina hipertónica (SSH) en conjunto con dosis altas de diuréticos de asa, como medida terapéutica temida por sus posibles repercusiones sobre la función renal y posible sobrecarga de sodio. Objetivos: Determinar si el uso de solución salina hipertónica en pacientes con falla cardiaca aguda e hipervolemia genera un deterioro de la función renal. Determinar la respuesta del Pro-BNP ante el uso de la solución salina hipertónica en pacientes con falla cardiaca aguda como marcador de respuesta terapéutica. Determinar si el uso de solución salina hipertónica aumenta la diuresis sin generar cambios importantes en el sodio. Se muestran datos de pacientes con insuficiencia cardiaca aguda descompensada, que tras no presentar mejoría con altas dosis de diurético de asa en bolo, se les aplicó la solución hipertónica como adyuvante a este tratamiento. Se toma un total de 26 pacientes analizando datos generales clínicos y de laboratorio, se valoran curvas con la respuesta diurética y por parámetros de laboratorio a las 48 y 72 horas. El uso de solución salina hipertónica consigue un aumento de más de un 200% de la diuresis en 24 horas, con un descenso del Pro BNP de más de un 60% a las 48 horas, sin mostrar un cambio importante en los niveles de creatinina, nitrógeno ureico y sodio. Se requirió reposición de potasio en la totalidad de los pacientes. Se concluye que la infusión de furosemida más solución hipertónica es efectiva tanto en disminuir niveles de NT Pro-BNP en los pacientes, como en generar un aumento en el volumen de diuresis. La principal complicación fue la hipokalemia, sin cambios considerables en el valor de sodio, creatinina y nitrógeno ureico séricos.

Abstract Uso de Solución Hipertónica en pacientes con insuficiencia cardiaca aguda como terapia adyuvante a altas dosis de diuréticos Acute decompensated heart failure (AHF) is a common cause of hospitalization, with significant repercussions on health systems. Acute management is based on the reduction of blood volume with loop diuretics; however, a percentage of patients show resistance or do not achieve the expected clinical response with this treatment. One of the measures that has proven to be effective in this context is the use of hypertonic saline (HSS) in conjunction with high doses of loop diuretics, as a therapeutic measure feared due to its possible repercussions on kidney function and possible sodium overload. Objetives: To determine if the use of hypertonic saline in patients with acute heart failure and hypervolemia leads to a deterioration in renal function. To determine the response of Pro-BNP to the use of hypertonic saline in patients with acute heart failure as a marker of therapeutic response. Determine if the use of hypertonic saline increases urine output without causing significant changes in sodium. Data are shown from patients with acute decompensated heart failure, who after not presenting improvement with high doses of bolus loop diuretic, the hypertonic solution was applied as an adjunct to this treatment. A total of 26 patients are taken analyzing general clinical and laboratory data, curves with the diuretic response and by laboratory parameters are evaluated at 48 and 72 hours. The use of hypertonic saline solution achieves an increase of more than 200% in diuresis in 24 hours, with a decrease in Pro BNP of more than 60% at 48 hours, without showing a significant change in creatinine levels, urea nitrogen and sodium. Potassium replacement was required in all patients. It is concluded that the infusion of furosemide plus hypertonic solution is effective both in reducing levels of NT Pro-BNP in patients, and in generating an increase in the volume of diuresis. The main complication was hypokalemia, without significant changes in serum sodium, creatinine, and urea nitrogen.

Effects of age and caloric restriction on the cardiac and coronary response to endothelin-1 in rats.

BACKGROUND AND AIMS: Aging is associated with alterations in the cardiovascular system such as increased vasoconstriction and decreased vasodilatation. Some of these changes are partially reversed by caloric restriction. Endothelin-1 is a potent vasoconstrictor which levels increased with age. The aim of this study is to analyze the role of endothelin-1 in the cardiac and coronary changes induced by age and whether these changes may be attenuated by a three-month caloric restriction. METHODS AND RESULTS: Hearts from young (3 months old), aged (24 months old) and aged rats after 3 months of caloric restriction were perfused according to the Langendorff technique. Coronary vasoconstriction to endothelin-1 was reduced in old rats, and endothelin-1 increased myocardial contractility (dP/dt) and heart rate in old but not in young rats. These changes observed in old rats were partly reversed by caloric restriction. Also, in the myocardial tissue of old rats the gene expression of endothelin-1, inducible nitric oxide synthase (iNOS) and tumor necrosis factor alpha (TNF-a) was increased, and the gene expression of endothelin ETB receptors and endothelial nitric oxide syntase (eNOS) was reduced, compared with young rats. Aging induced changes in the expression of ETB receptors and eNOS were reversed by caloric restriction. CONCLUSIONS: These results suggest that aging produces alterations in myocardial and coronary responses to endothelin-1, that may be related to changes in expression of nitric oxide synthases and/or endothelin receptor subtypes, with some of these changes being prevented by caloric restriction.

Purinergic component in the coronary vasodilatation to acetylcholine after ischemia-reperfusion in perfused rat hearts.

To determine the involvement of purinergic receptors in coronary endothelium-dependent relaxation, the response to acetylcholine (1 × 10(-8) to 3 × 10(-7)M) was recorded in isolated rat hearts perfused according to the Langendorff procedure before and after 30 min of ischemia and 15 min of reperfusion and after the inhibition of nitric oxide synthesis with L-NAME (10(-4)M), in the absence and presence of the antagonist of purinergic P2X receptors, PPADS (3 × 10(-6)M), and of the antagonist of purinergic P2Y receptors, Reactive Blue 2 (3 × 10(-7)M). In control conditions, the relaxation to acetylcholine was not altered by PPADS or Reactive Blue 2. The relaxation to acetylcholine was reduced after ischemia-reperfusion, and, in this condition, it was further reduced by treatment with PPADS or Reactive Blue 2. Likewise, the relaxation to acetylcholine was reduced by L-NAME, and reduced further by Reactive Blue 2 but not by PPADS. These results suggest that the relaxation to acetylcholine may be partly mediated by purinergic receptors after ischemia-reperfusion, due to the reduction of nitric oxide release in this condition.

Tyrosine phosphorylation modulates the vascular responses of mesenteric arteries from human colorectal tumors.

The aim of this study was to analyze whether tyrosine phosphorylation in tumoral arteries may modulate their vascular response. To do this, mesenteric arteries supplying blood flow to colorectal tumors or to normal intestine were obtained during surgery and prepared for isometric tension recording in an organ bath. Increasing tyrosine phosphorylation with the phosphatase inhibitor, sodium orthovanadate produced arterial contraction which was lower in tumoral than in control arteries, whereas it reduced the contraction to noradrenaline in tumoral but not in control arteries and reduced the relaxation to bradykinin in control but not in tumoral arteries. Protein expression of VEGF-A and of the VEGF receptor FLT1 was similar in control and tumoral arteries, but expression of the VEGF receptor KDR was increased in tumoral compared with control arteries. This suggests that tyrosine phosphorylation may produce inhibition of the contraction in tumoral mesenteric arteries, which may increase blood flow to the tumor when tyrosine phosphorylation is increased by stimulation of VEGF receptors.

Coronary response to diadenosine triphosphate after ischemia-reperfusion in the isolated rat heart.

Diadenosine triphosphate (Ap3A) is a vasoactive mediator stored in platelet granules that may be released during coronary ischemia-reperfusion. To study its coronary effects in such circumstances, rat hearts were perfused in a Langendorff preparation and the coronary response to Ap3A (10(-7)-10(-5) mol/L) was recorded. Both at basal coronary resting tone and after precontraction with 11-dideoxy-1a,9a-epoxymethanoprostaglandin F(2)(α) (U46619), Ap3A produced concentration-dependent vasodilation in the heart, which was attenuated following ischemia-reperfusion. Ap3A-induced relaxation was also attenuated in control conditions and after ischemia-reperfusion by the purinergic P2Y antagonist reactive blue 2 (2 × 10(-6) mol/L), the P2Y(1) antagonist MRS 2179 (10(-5) mol/L), the nitric oxide synthesis inhibitor N-omega-nitro-l-arginine methyl ester (l-NAME; 10(-4) mol/L) and the ATP-dependent potassium channel blocker glibenclamide (10(-5) mol/L). These results suggest that Ap3A induces coronary vasodilation, an effect attenuated by ischemia-reperfusion due to the functional impairment of purinergic P2Y receptors and K(ATP) channels, and/or reduced nitric oxide release. This impairment of vasodilation may contribute to the coronary dysregulation that occurs during ischemia-reperfusion.

Nitric oxide-mediated relaxation to lactate of coronary circulation in the isolated perfused rat heart.

The objective of this study was to analyze the effects of lactate on coronary circulation. Rat hearts were perfused in a Langendorff preparation, and the coronary response to lactate (3-30 mM) was recorded after precontracting coronary vasculature with 11-dideoxy-1a,9a-epoxymethanoprostaglandin F2α (U46619), in the presence or the absence of the inhibitor of nitric oxide synthesis, N-omega-nitro-l-arginine methyl ester (l-NAME, 10 M), the blocker of Ca-dependent potassium channels, tetraethylammonium (TEA, 10 M), or the blocker of adenosine triphosphate-sensitive potassium channels, glybenclamide (10 M). The effects of lactate were also studied in isolated segments of rat coronary arteries that were precontracted with U46619, with or without endothelium. In perfused hearts, lactate induced concentration-dependent coronary vasodilatation and a reduction in myocardial contractility (left ventricular developed pressure and dP/dt) without altering the heart rate. Coronary vasodilatation in response to lactate was reduced by l-NAME but unaffected by TEA or glybenclamide. The effects of lactate on myocardial contractility were unchanged by l-NAME, TEA, or glybenclamide. In isolated coronary artery segments, lactate also produced relaxation, an effect attenuated by removing the endothelium. Together these findings suggest that lactate exerts coronary vasodilatory effects through the release of endothelial nitric oxide, independently of potassium channels. These findings may be relevant for the regulation of coronary circulation when lactate levels are elevated.

Coronary response to diadenosine tetraphosphate after ischemia-reperfusion in the isolated rat heart.

Diadenosine tetraphosphate (AP4A) is a vasoactive mediator that may be released from platelet granules and that may reach higher plasma concentrations during coronary ischemia-reperfusion. The objective of this study was to analyze its coronary effects in such conditions. To this, rat hearts were perfused in a Langendorff preparation and the coronary response to Ap4A (10(-7)-10(-5) M) was recorded. In control hearts, Ap4A produced concentration-dependent vasodilatation both at the basal coronary resting tone and after precontracting coronary vasculature with 11-dideoxy-1a,9a-epoxymethanoprostaglandin F2α (U46619), and this vasodilatation was reduced by reactive blue 2 (2×10(-6) M), glibenclamide (10(-5) M), H89 (10(-6) M), U73122 (5×10(-6) M) and endothelin-1 (10(-9) M), but not by L-NAME (10(-4) M), isatin (10(-4) M), GF109203x (5×10(-7) M), or wortmannin (5×10(-7) M). After ischemia-reperfusion, the vasodilatation to Ap4A diminished, both in hearts with basal or increased vascular tone, and in this case the relaxation to Ap4A was not modified by reactive blue 2, L-NAME, glibenclamide, isatin, H89, GF109203x or wortmannin, although it was reduced by U73122 and endothelin-1. UTP produced coronary relaxation that was also reduced after ischemia-reperfusion. These results suggest that the coronary relaxation to Ap4A is reduced after ischemia-reperfusion, and that this reduction may be due to impaired effects of KATP channels and to reduced response of purinergic P2Y receptors.

Coronary response to diadenosine pentaphosphate after ischaemia-reperfusion in the isolated rat heart.

AIMS: Diadenosine polyphosphates are vasoactive mediators that may be released from platelet granules and which may be present at higher concentrations during coronary ischaemia-reperfusion. The objective of this study was to analyse their effects in such conditions. METHODS AND RESULTS: Rat hearts were perfused in a Langendorff preparation and the response to diadenosine pentaphosphate (Ap5A, 10(-7)-10(-5) M) was recorded. In control hearts, Ap5A produced a small, transient coronary vasoconstriction followed by marked vasodilatation, as well as a reduction in the left ventricular developed pressure dP/dt and heart rate, both at the basal coronary resting tone or after pre-contracting coronary arteries with 9,11-dideoxy-11alpha, 9alpha-epoxymethanoprostaglandin F2alpha (U46619). After ischaemia-reperfusion, the vasoconstriction in response to Ap5A was augmented and vasodilatation diminished, both in hearts with basal or increased vascular tone. The pyridoxal derivative P(2) purinoceptor antagonist, pyridoxalphosphate-6-azophenyl-2',4'-disulfonic acid (PPADS, 3 x 10(-6) M), inhibited this vasoconstriction, while the antagonist of purinergic P(2Y) receptors, Reactive Blue 2 (2 x 10(-6) M), inhibited the vasodilatation, both before and after ischaemia-reperfusion. The antagonist of nitric oxide synthesis N-omega-nitro-L- arginine methyl ester (L-NAME, 10(-4) M) did not modify the response to Ap5A, whereas the cyclooxygenase inhibitor, meclofenamate (2 x 10(-6) M), reduced contraction and increased the relaxation in response to Ap5A after ischaemia-reperfusion but not under control conditions. CONCLUSION: Ischaemia-reperfusion reduces the vasodilatory response to Ap5A and increases the vasoconstriction provoked due to a reduced influence of purinergic P(2Y) receptors and/or to the production of vasoconstrictor prostanoids.

Response to endothelin-1 in arteries from human colorectal tumours: role of endothelin receptors.

To examine the reaction of tumour arteries to endothelin-1, we obtained arteries supplying blood flow to colorectal tumours from patients, as well as mesenteric arteries supplying the normal colon tissue from the same patients and mesenteric arteries from patients without a colorectal tumour pathology. The contraction in response to endothelin-1 and the relaxation produced by bradykinin was recorded in each of these arteries. Accordingly, the sensitivity to endothelin-1 but not the maximal response, was higher in the arteries supplying colorectal tumours than in mesenteric arteries supplying normal colon or in mesenteric arteries from patients with no tumour pathology. The contraction produced by endothelin-1 was not modified by exposure to L-NAME or meclofenamate in arteries supplying both the tumour and the normal colon. The endothelin ET(A) andET(B) receptors were expressed similarly in arteries supplying the tumour or normal colon. However, the antagonist of the endothelin ET(B) receptors BQ788 (10(-6) M) decreased the contractions in the arteries supplying the tumour but not in those supplying the normal colon. By contrast, the antagonist of endothelin ET(A) receptors BQ123 (10(-6) M) reduced the contraction equally in both these types of arteries. Likewise, in arteries precontracted with U46619, the relaxation in response to bradykinin was similar in all three types of arteries. Together, these results suggest that the arteries supplying human colorectal tumours are more sensitive to endothelin-1, which could be due to the enhanced activity of endothelin ET(B) receptors in the absence of any change in the modulatory effect of nitric oxide or prostanoids in the arterial response to this peptide.

Goat cerebrovascular reactivity to ADP after ischemia-reperfusion. Role of nitric oxide, prostanoids and reactive oxygen species.

To analyze the cerebrovascular effects of ischemia-reperfusion, cerebrovascular reactivity to ADP was studied after inducing 60-min occlusion followed by 60-min reperfusion of the left middle cerebral artery (MCA) in anesthetized goats. In 12 goats, at the end of reperfusion, left MCA resistance was decreased by 19%, and reactive hyperemia to 5- and 10-s occlusions as well as the cerebral vasodilatation to ADP (0.03-0.3 microg) but not to sodium nitroprusside (0.3-3 microg) was decreased. In 28 animals, killed at the end of reperfusion, segments 3-mm long were obtained from the left (ischemic) and right (control) MCA, prepared for isometric tension recording, and precontracted with the thromboxane A2 analogue U46619. The relaxation to ADP (10(-8) to 10(-5) M) but not to sodium nitroprusside (10(-8) to 10(-4) M) was lower in ischemic arteries. L-NAME (inhibitor of nitric oxide synthesis, 10(-4) M), charybdotoxin (10(-7) M)+apamin (10(-6) M) (blockers of KCa), or catalase (1000 U/ml) reduced the relaxation to ADP only in control arteries. Charybdotoxin+apamin further augmented the L-NAME-induced reduction in the relaxation to ADP in control arteries. The inhibitor of cyclooxygenase meclofenamate (10(-5) M) increased the relaxation to ADP only in ischemic arteries. The superoxide dismutase mimetic tiron (10(-2) M) increased the ADP-induced relaxation only in ischemic arteries. Therefore, it is suggested that ischemia-reperfusion produces cerebrovascular endothelial dysfunction, which may be associated with decreased nitric oxide bioavailability, decreased release of an EDHF, and increased production of vasoconstrictor prostanoids. All these alterations may be related in part with an increased production of superoxide anion.

Valoración de estudios radiológicos solicitados por un servicio de emergencias / Valuation of radiological studies, asked by a services of emergency

Análisis de los estudios radiológicos convencionalesmás frecuentes solicitados por un servicio de emergencias así como de sus solicitudes, en un hospital y período determinado. Se tomó una muestra al azar de 760 estudios radiológicos convencionales solicitados por el servicio de emergencias del Hospital Max Peranta durante un período de 9 semanas. Se encontró que las patologías del sistema óseo fue el principal motivo de solicitud de examen radiológico con un 65,44 por ciento de los estudios (incluyendo aquí extremidades superiores e inferiores, cráneo, columna vertebral, pelvis y tórax óseo), seguido por la patología de origen torácico (28,4 por ciento). La gran mayoría de los estudios solicitados no presentaron alteraciones radiológicas (71,88 por ciento). La principal patología encontrada a nivel osteo-articular fue fracturas (13.93 por ciento), a nivel torácico el diagnóstico más frecuente fue cardiomegalia (11.57 por ciento), EPOC (10,18 por ciento), y bronconeumonías (6,94 por ciento). Tomando en cuenta los estudios con alteraciones radiológicas, un 49,52 por ciento presentaban patologías agudas o traumáticas y un 50,47 por ciento patologías crónicas. Se prestaron 57 por ciento de las solicitudes con datos clínicos insuficientes, incompletos o ilegibles. La radiografía convencional juega un papel importante en el diagnóstico de paciente de emergencias, especialmente en patología traumática y cardio-pulmonar. Un estudio radiológico sin alteraciones evidentes es parte importante en el manejo del paciente de un servicio de emergencias. Debe hacerse conciencia en el personal de emergencias para aportar completos y adecuados datos clínicos en las solitudes.