[Noninvasive positive pressure ventilation in postoperative period of tracheal surgery]. / Ventilación con presión positiva no invasiva en el postoperatorio de cirugía traqueal.

OBJECTIVES: Reconstructive surgery of the airway often means prolonged periods of intubation during the post-operatory period, increasing the needs for drugs and favoring the appearance of infectious complications. We present an original system of ventilatory support with non-invasive positive pressure ventilation (NIPPV) using in patients subjected to reconstructive surgery of the airway. PATIENTS AND METHODS: A retrospective study in patients undergoing reconstructive procedures of the airway in the year 2009 was carried out. We exclude those treated endoscopically and those who had vascular rings. The positive pressure mechanism used in the Surgery Critical Care Unit was a design made by the unit based on the circuit devised by Mapleson that provides optimum levels of ventilation without need for connection to a respiratory. We analyze the results, postoperatory intubation time, time dependent on NIPPV and medical treatment received. RESULTS: A total of 7 patients (1 Female and 6 Males) with median age of 1.6 (0.1-7.5) years were included. The diagnoses were: 4 subglottic stenosis, 2 had tracheal stenosis and 1 subcarinal stenosis with involvement of both principal bronchioles. The techniques used were: laryngotracheoplasty with costal cartilage graft (4), tracheoplasty with costal cartilage (1) and sliding tracheoplasty (2) with bilateral bronchoplasty in one of them. The mean time of nasotracheal intubation was 3 days, and mean time of NIPPV was 2.3. No patient required reintubation and none had infectious complications. CONCLUSIONS: Ventilatory support by VPPNI allows effective extubation in these patients, it being possible to maintain a safe airway. Infectious complications, frequent in prolonged intubations, were not observed in any of the cases.

[Acute myocardial infarction complicating radiofrequency catheter ablation in a girl]. / Infarto agudo de miocardio tras ablación por radiofrecuencia de vía cardiaca anómala en un niño.

Paroxysmal supraventricular tachycardia is the most common tachyarrhythmia in childhood and adolescence. The current treatment of choice for managing and preventing frequent recurrences is radiofrequency catheter ablation, which provides a definitive solution in most cases. This technique is very effective but not devoid of potential complications, particularly in children and adolescents. We report the case of a 3-year-old girl who suffered acute myocardial infarction after occlusion of the right coronary artery during this procedure. We describe intraoperative and postoperative management. Progress was good and the patient was discharged 14 days after ablation.

Efectividad de un programa de superación en la prevención de infecciones asociadas a la asistencia sanitaria aplicando la teoría ambientalista de Florence Nightingale / Effectiveness of an improvement program in the prevention of infections associated with health care applying the environmentalist theory of Florence Nightingale

Introducción: Las infecciones asociadas a la asistencia sanitaria son consideradas uno de los indicadores de calidad en la atención hospitalaria, estas tienen un origen multifactorial complejo, cuyos factores involucrados son difíciles de modificar; sin embargo, existe la posibilidad de intervenir en el personal. Objetivo: Evaluar la efectividad de un programa de superación en la prevención de infecciones asociadas a la asistencia sanitaria aplicando la teoría ambientalista de Florencia Nightingale. Métodos: Se realizó una investigación preexperimental longitudinal en servicios de mayor incidencia con estas infecciones en el Hospital General Mártires del 9 de abril, de Villa Clara en el periodo 2019-2020. La población 139 profesionales de enfermería con una muestra de 125, a los que se aplicó una encuesta y se realizó una observación participante. Asimismo, se recogió además el criterio de especialistas de grupos nominales. Resultados: 78,40 % licenciados en enfermería, 49,60 % con menos de 5 años de desempeño laboral. Sobre definición, localizaciones y gérmenes más frecuentes de IAAS antes de la capacitación 84,00 % tenían inadecuado conocimiento y después 92,80 %. En normas de prevención y control antes de aplicada la capacitación el lavado de manos sólo alcanzo 24,80 %; después 96,00 %. En la observación de procederes 77,60 % recibieron evaluación de inadecuado, perfeccionando estas técnicas en un 90,40 % después de aplicada la misma. La afectividad de la superación 95.20 %Conclusión: El programa de superación en la prevención de infecciones asociadas a la asistencia sanitaria aplicando la teoría ambientalista de Florencia Nightingale resultó efectivo, al actualizar conocimientos, modificar prácticas y actitudes al fomentar un entorno cordial.

Introduction: Health care-associated infections are considered one of the quality indicators in hospital care, they have a complex multifactorial origin, whose factors involved are difficult to modify, however, there is the possibility of intervening in the staff. Objective: To evaluate the effectiveness of an improvement program in the prevention of infections associated with health care applying the environmentalist theory of Florence Nightingale. Methods: A longitudinal pre-experimental investigation was carried out in services with the highest incidence of these infections at the Hospital General Mártires del 9 de abril, in Villa Clara in the period 2019-2020. The population was 139 nursing professionals with a sample of 125, to whom a survey was applied and a participant observation was carried out. The criteria of nominal group specialists were also collected.Results: 78.40% were nursing graduates, 49.60% with less than 5 years of work performance. About the definition, locations and most frequent germs of IAAS before the training, 84.00% had inadequate knowledge and after 92.80%. In prevention and control standards, before the training was applied, hand washing only reached 24.80% and after 96.00%. In the observation of procedures, 77.60% received an evaluation of inadequate, perfecting these techniques in 90.40% after applying it. The affectivity of overcoming was 95.20%. Conclusions: The improvement program in the prevention of infections associated with health care applying the environmentalist theory of Florence Nightingale was effective, updating knowledge, modifying practices and attitudes and promoting a pleasant environment

Methylazoxymethanol: effect on the immune response of rats to human serum albumin.

Inbred male F344 rats treated with 20 mg methylazoxymethanol (MAM)/kg body weight showed minimal damage to DNA in bone marrow, spleen, and thymus and no suppression of the humoral immune response to human serum albumin (HSA). At high doses of MAM (40, 60, and 80 mg/kg), damage to DNA of bone marrow, spleen, and thymus was noted. The effect on the humoral immune responses was nonuniform. Some rats responded normally by eliciting precipitating antibodies, whereas others responded by synthesizing nonprecipitating antibodies at low levels. The production of nonprecipitating antibodies may indicate a restriction of the recognition of HSA antigenic determinants in rats given injections of MAM prior to immunization. The restriction may be a consequence of suppression or elimination of certain clones of lymphocytes responsible for recognition of certain antigenic determinants. This interference in some clones of lymphocytes would result in the synthesis of antibodies against one or two antigenic sites on the HSA and the concomitant inability of the produced antibodies to form complete lattice structure with antigen.

Lack of interaction of angiotensin converting enzyme inhibitors with muscarinic and neuropeptide Y receptors.

In studies conducted in patients undergoing cardiac catheterizations, some hemodynamic changes were observed after the acute sublingual administration of the angiotensin converting enzyme inhibitors (ACEI) captopril, enalapril, and lisinopril. These changes consisted of an increase in pulmonary artery pressure, pulmonary vascular resistance (PVR) and induction of hypoxia. The pressure changes were transitory and disappeared after 25 min. The possible mechanisms involved in these changes may relate to interactions of the ACEI with peripheral receptor systems for hormones and neurotransmitters. We have thus undertaken the task of evaluating the potential effect of ACEI on biological receptor molecules. We have begun with studies on muscarinic receptors, and the recently characterized neuropeptide Y (NPY) receptors of endothelial cells. Equilibrium binding assays with 3H-QNB have been conducted for muscarinic receptors using rat brain synaptosomes, due to its expression of multiple muscarinic receptors subtypes. In addition 125BH-NPY binding assays were conducted on intact adrenal medullary endothelial cells. Enalapril and captopril, 10(-7) to 10(-3) M, were not able to produce significant inhibition of either muscarinic or NPY receptor probes. The paradoxical changes elicited by sublingual ACEI seems not to involve interaction with muscarinic or NPY receptors.

[Usefulness of radiologic monitoring of epidural catheters using epidurography]. / Utilidad del control radiológico de los catéteres epidurales mediante epidurografía.

INTRODUCTION: Peridural analgesia involves a segmental block which at the thoracic level allows for early pulmonary recovery after chest or high abdominal surgery. The approach is difficult in children for reasons related to anatomy, maintenance, insertion of the catheter and dosing. OBJECTIVE: To report the radiologic monitoring of epidural catheter placement by epidurography as a technique for placing the epidural catheter in 17 patients for whom postoperative analgesia was to be provided by the same route. PATIENTS AND METHODS: Eighteen children (aged from 2 to 12) were given general anesthesia followed by epidural anesthesia. After catheterization of the epidural space, 1 or 1-5 ml of contrast was injected. Immediately afterwards an X-ray of the thoracic or lumbar spinal column, as appropriate to each case, was obtained. Epidural analgesia was provided with a mixture of bupivacaine 0.125% and fentanyl, in continuous perfusion or in fractionated doses. RESULTS: Placement of the catheter tip was confirmed in 17 cases by visualization of symmetry and the presence of contrast medium in the epidural space. In one case we observed extravasation of contrast medium, which had invaded the paravertebral space. The course was linear in 17 cases, with no looping. No complications related to injection of contrast medium were observed. CONCLUSIONS: Epidurography provides objective monitoring of tip placement and trajectory of epidural catheters, advantages which argue in favor of more frequent application of this imaging technique.

L-DOPA Uptake in Astrocytic Endfeet Enwrapping Blood Vessels in Rat Brain.

Astrocyte endfeet surround brain blood vessels and can play a role in the delivery of therapeutic drugs for Parkinson's disease. However, there is no previous evidence of the presence of LAT transporter for L-DOPA in brain astrocytes except in culture. Using systemic L-DOPA administration and a combination of patch clamp, histochemistry and confocal microscopy we found that L-DOPA is accumulated mainly in astrocyte cell bodies, astrocytic endfeet surrounding blood vessels, and pericytes. In brain slices: (1) astrocytes were exposed to ASP(+), a fluorescent monoamine analog of MPP(+); (2) ASP(+) taken up by astrocytes was colocalized with L-DOPA fluorescence in (3) glial somata and in the endfeet attached to blood vessels; (4) these astrocytes have an electrogenic transporter current elicited by ASP(+), but intriguingly not by L-DOPA, suggesting a different pathway for monoamines and L-DOPA via astrocytic membrane. (5) The pattern of monoamine oxidase (MAO type B) allocation in pericytes and astrocytic endfeet was similar to that of L-DOPA accumulation. We conclude that astrocytes control L-DOPA uptake and metabolism and, therefore, may play a key role in regulating brain dopamine level during dopamine-associated diseases. These data also suggest that different transporter mechanisms may exist for monoamines and L-DOPA.

Effect of albumin on the width of water channels in venous endothelium.

The effect of bovine and dog albumin and plasma was measured on the hydraulic conductivity (Lp) and electrical resistance (R) across the endothelium of the dog vena cava. An estimate of changes in size of transendothelial water channels was then obtained by combining Lp and R values. Dogs were anesthetized with pentobarbital sodium to surgically remove their thoracic inferior vena cava. Lp was measured by a gravimetric method at constant vessel volume. R was obtained from the transvascular voltage changes caused by current pulses. Lp measured at the beginning of the experiments was 0.97 +/- 0.17 X 10(-7) cm.s-1.cmH2O-1 in plasma and 2.75 +/- 0.48 X 10(-7) cm.s-1.cmH2O-1 in Ringer solution. Bovine albumin produced an 18% reduction in Lp relative to its value in Ringer solution. Dog albumin and plasma lowered Lp 50 and 54%, respectively. The differences were statistically significant with P less than 0.05. R increased from 15.17 +/- 7.0 to 26.5 +/- 16.0 omega.cm2 in dog albumin and 27.4 +/- 9.6 omega.cm2 in dog plasma. Calculations using a model for the transendothelial channel and equations for Lp and R showed a decrease in channel width of 172 A due to the protein. This could be accounted for by the thickness of a monolayer of albumin absorbed to the channel walls. Results suggest that the permeability response to plasma proteins is a general property of vascular endothelium.

Specific 125I neuropeptide Y binding to intact cultured bovine adrenal medulla capillary endothelial cells.

OBJECTIVE: This study involved the pharmacological detection and characterization of binding sites for the neuromodulator neuropeptide Y (NPY) in an in vitro preparation of capillary endothelial cells derived from bovine adrenal medulla. METHODS: Equilibrium binding assays were conducted on intact cells with 125I Bolton-Hunter labeled NPY (125I-BH-NPY). The specificity of the high-affinity binding site was evaluated in competition experiments with cold NPY, (Leu31, Pro34)NPY (a Y1 receptor ligand, Y1RL), NPY13-36 (a Y2 receptor ligand, Y2RL), and two other members of the pancreatic polypeptide-fold (PP-fold) family: peptide YY (PYY) and avian pancreatic polypeptide (APP). Forskolin-stimulated adenylate cyclase activity was assessed to detect the participation of this second messenger pathway in the neuromodulator action at the studied cell preparation. RESULTS: Nonlinear regression analysis of the binding data indicated the existence of high-affinity binding sites with an equilibrium dissociation constant (Kd) value of 39.00 +/- 12.84 nM and a maximal binding (Bmax) of 489.89 +/- 155.49 fmol/10(6) cells (mean +/- SE, n = 6). NPY, Y1RL, and PYY displayed a concentration that inhibits the specific binding by 50% IC50 (nM) values of 4.06 +/- 1.66 (n = 4), 2.94 +/- 0.75 (n = 5), and 18.36 +/- 10.36 (n = 3), respectively. APP and Y2RL were unable to compete with 125I-NPY in the concentration range 0.001-1 microM. Further evaluation of second messenger pathways suggested that NPY binding sites in this model are coupled to the inhibition of adenylate cyclase. NPY significantly inhibited the forskolin-stimulated adenosine cyclic 3',5'-(hydrogen phosphate) (cAMP) accumulation with a maximal effect of 37.03 +/- 6.28%, n = 5 and an IC50 of 5.96 +/- 1.87 nM. The Y1RL produced a comparable response (IC50 = 5.35 +/- 1.39 nM, n = 4; maximal inhibition of 61.05 +/- 13.03%) and Y2LR had no detectable effect at a similar concentration range. CONCLUSIONS: The results demonstrate the existence of a Y1 receptor in the adrenal medulla capillary endothelial cells, which may be relevant to the postjunctional effect of NPY on this gland.

Hydraulic conductivity of venous endothelium as measured with a volume clamp method.

Hydraulic conductivity (Lp) of cava vein endothelium was obtained with a new method that measures fluid flow at constant volume. Dogs were anesthetized with pentobarbital sodium. A vessel segment was removed, cannulated, and hung free from a force transducer calibrated to measure weight. Hydraulic pressure difference drove fluid across the vessel wall. This fluid was washed out from the vessel surface by external perfusion, causing a weight loss that was transmitted to a Grass polygraph through the force transducer. Shifting the polygraph balance caused a voltage output which was used to activate a controller operating a microsyringe pump. By injecting fluid into the vessel lumen, this servomechanism counteracted weight changes and kept volume and pressure at a fixed level. Recording the volume injected allowed continuous monitoring of fluid flow. This avoided the problems caused by frequent pressure and volume resetting in previous methods. Fluid flow was a linear function of the applied pressure (r = 0.87). Lp was 0.91 +/- 0.05 (SD) X 10-7 cm X s-1 X cmH2O-1. This value was very similar to those in continuous capillaries and arterial endothelium.

Simvastatin releases Ca2+ from a thapsigargin-sensitive pool and inhibits InsP3-dependent Ca2+ mobilization in vascular smooth muscle cells.

Simvastatin (SV), an inhibitor of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase activity inhibits migration and proliferation of vascular smooth muscle cells (SMC). To investigate whether these effects of SV are related to inhibition of cell calcium mobilization, cultured SMC obtained from rat aorta were loaded with Fura-2 to determine the basal cytosolic free calcium levels ([Ca2+]i) and the agonist-stimulated Ca2+ mobilization. SV (20 mu M) transiently increased cytosolic free calcium, an effect that depends mainly on intracellular calcium release (68%). This effect of SV was markedly reduced (75%) by thapsigargin, an inhibitor of the Ca2+ ATPase of inositol 1,4,5-triphosphate (InsP3)-sensitive calcium pools. Incubation of cells with SV (15 min) inhibited the mobilization of Ca2+ by angiotensin II, platelet-derived growth factor, and vasopressin (IC50 = 5 mu M). SV did not affect inositol trisphosphate (InsP3) levels or modify its generation by angiotensin II (Ang II) and vasopressin. Furthermore, in saponin-permeabilized cells, SV abolished the release of calcium by 2,3-dideoxy-InsP3. SV reduced the effect of thapsigargin on InsP3-sensitive stores by 67%, suggesting that SV depletes these calcium pools. The inhibitory effect of SV on calcium mobilization was prevented by coincubation of cultured cells (24 h) with 1 mM mevalonic acid, the product of HMG-CoA reductase activity. These results support the notion that SV inhibits [corrected] the migration and proliferation of SMC by directly affecting cell Ca2+.

Lack of interaction of angiotensin converting enzyme inhibitors with muscarinic and neuropeptide Y receptors

In studies conducted in patients undergoing cardiac catheterizations, some hemodynamic changes were observed after the acute sublingual administration of the angiotensin converting enzyme inhibitors (ACEI) captopril, enalapril, and lisinopril. These changes consisted of an increase in pulmonary artery pressure, pulmonary vascular resistance (PVR) and induction of hypoxia. The pressure changes were transitory and disappeared after 25 min. The possible mechanisms involved in these changes may relate to interactions of the ACEI with peripheral receptor systems for hormones and neurotransmitters. We have thus undertaken the task of evaluating the potential effect of ACEI on biological receptor molecules. We have begun with studies on muscarinic receptors, and the recently characterized neuropeptide Y (NPY) receptors of endothelial cells. Equilibrium binding assays with 3H-QNB have been conducted for muscarinic receptors using rat brain synaptosomes, due to its expression of multiple muscarinic receptors subtypes. In addition 125BH-NPY binding assays were conducted on intact adrenal medullary endothelial cells. Enalapril and captopril, 10(-7) to 10(-3) M, were not able to produce significant inhibition of either muscarinic or NPY receptor probes. The paradoxical changes elicited by sublingual ACEI seems not to involve interaction with muscarinic or NPY receptors