Auditoría de oxígenoterapia de pacientes hospitalizados en establecimientos del Servicio de Salud Talcahuano / Audit on oxygen therapy in hospitalized patients from Public Health Service of Talcahuano, Chile

El oxígeno (O2) es una de las drogas más utilizadas en clínica, su uso no está exento de riesgos. Existen guias internacionales para su uso, pero en nuestro medio no sabemos si se aplican. Nuestro objetivo fue describir la forma en que se utiliza y controla la oxígenoterapia en los 3 hospitales de la red del Servicio de Salud Talcahuano. Aplicamos una encuesta un día de agosto de 2016 a los pacientes hospitalizados en las instituciones de la red que recibían O2 en ese momento. Se recolectaron datos sobre la prescripción, administración y seguimiento de la terapia de O2. De los 381 pacientes auditados, un 13,7% recibía oxígenoterapia. Los diagnósticos más frecuentes fueron de causa respiratoria (46,15%) y cardiológica (25%). La indicación la dio un médico en 88,5% de los casos y en un 3,8% no había registro. En un 17,3% de los pacientes no había fundamento para la indicación. Se indicó una dosis fija en el 75% con una meta de SaO2 en el 50%, siendo naricera y máscara de Venturi los métodos de administración más frecuentes monitorizándose con oximetría de pulso en los hospitales menos complejos y gasometría arterial en el hospital terciario. La duración media de la oxígenoterapia fue de 7,8 días. Habiendo un buen fundamento y control de la oxígenoterapia aún no se indican metas a obtener. No hay un buen registro de la indicación ni de los cambios realizados. Creemos útil la realización periódica de este tipo de control para optimizar su uso evitando los potenciales efectos adversos en los pacientes.

Abstract Oxygen is a commonly used drug in clinics and its use must be judicious. There are guidelines for oxygen therapy but we ignore if these are respected in our country. We conducted an audit of oxygen therapy by applying a survey to 381 patients in the three hospitals of Talcahuano Public Health Service. The day of the audit 13.7% of the hospitalized patients were on oxygen, most of them with respiratory (46.15%) or cardiovascular (25%) diseases. Indication of O2 administration was given by a physician in 88.5% and there was not registry in 3.8% of the cases. There was not foundation for supplying O2 in 13.3% of patients. A fixed dose was indicated in 75% of cases and 50% had an oximetry value as a target. Oxygen was administered in most of the cases by nasal prongs and Venturi masks. Monitoring was based on pulse oximetry in the less complex hospitals and on arterial blood gases in the tertiary hospital. 100% of patients at urgency ward were receiving a different dose from that indicated at their admission time and none of them had a registry of the new dose. Mean duration of therapy was 7.8 days. We believe our results might represent what is going on with oxygen therapy in our country; having a good foundation and monitoring, we still don t use targets and there is a bad system of registry. We think that it would be advisably to carry out audits on oxygen therapy at national level on regular basis.

Methylphenidate amplifies long-term potentiation in rat hippocampus CA1 area involving the insertion of AMPA receptors by activation of ß-adrenergic and D1/D5 receptors.

Methylphenidate (MPH, Ritalin©) is widely used in the treatment of Attention Deficit Hyperactivity Disorder and recently as a drug of abuse. Although the effect of MPH has been studied in brain regions such as striatum and prefrontal cortex (PFC), the hippocampus has received relatively little attention. It is known that MPH increases the TBS-dependent Long Term Potentiation (LTP) in the CA1 area. However, the cellular and molecular mechanisms involved in this process are still unknown. Using field potential recordings and western blot analysis in rat hippocampal slices of young rats, we found that acute application of MPH enhances LTP in CA3-CA1 synapses in a dose-dependent manner with an EC50 of 73.44±6.32 nM. Using specific antagonists and paired-pulse facilitation protocols, we observed that the MPH-dependent increase of LTP involves not only ß-adrenergic receptors activation but also post-synaptic D1/D5 dopamine receptors. The inhibition of PKA with PKI, suppressed the facilitation of LTP induced by MPH consistent with an involvement of the adenyl cyclase-cAMP-PKA dependent cascade downstream of the activation of D1/D5 receptors. In addition, samples of CA1 areas taken from slices potentiated with MPH presented an increase in the phosphorylation of the Ser845 residue of the GluA1 subunit of AMPA receptors compared to control slices. This effect was reverted by SCH23390, antagonist of D1/D5 receptors, and PKI. Moreover, we found an increase of surface-associated functional AMPA receptors. We propose that MPH increases TBS-dependent LTP in CA3-CA1 synapses through a polysynaptic mechanism involving activation of ß-adrenergic and D1/D5 dopaminergic receptors and promoting the trafficking and insertion of functional AMPA receptors to the plasma membrane.

Acutely applied MDMA enhances long-term potentiation in rat hippocampus involving D1/D5 and 5-HT2 receptors through a polysynaptic mechanism.

3,4-Methylenedioxymethamphetamine (MDMA, ecstasy) is a drug of abuse that induces learning and memory deficit. However, there are no experimental data that correlate the behavioral evidence with models of synaptic plasticity such as long-term potentiation (LTP) or long-term depression (LTD). Using field potential recordings in rat hippocampal slices of young rats, we found that acute application of MDMA enhances LTP in CA3-CA1 synapses without affecting LTD. Using specific antagonists and paired-pulse facilitation protocols we observed that the MDMA-dependent increase of LTP involves presynaptic 5-HT2 serotonin receptors and postsynaptic D1/D5 dopamine receptors. In addition, the inhibition of PKA suppresses the MDMA-dependent increase in LTP, suggesting that dopamine receptor agonism activates cAMP-dependent intracellular pathways. We propose that MDMA exerts its LTP-altering effect involving a polysynaptic interaction between serotonergic and dopaminergic systems in hippocampal synapses. Our results are compatible with the view that the alterations in hippocampal LTP could be responsible for MDMA-dependent cognitive deficits observed in humans and animals.

Componentes ocupacionales a evaluar en el proceso de tratamiento y rehabilitación del consumo problemático de drogas / Assessment of occupational components in the treatment and rehabilitation process of problematic drug abuse

La recolección de datos se llevó a cabo a través de la revisión de la literatura existente sobre el tema y una entrevista semiestructurada a siete Terapeutas Ocupacionales, con experiencia en el área de estudio. La entrevista se centró en los siguientes temas: Componentes Ocupacionales evaluados por terapeutasocupacionales durante el proceso de Tratamiento y Rehabilitación, modelos y evaluaciones utilizadas por terapeutas ocupacionales y Componentes Ocupacionales que muestran mayor déficit. Los resultados de esta investigación revelaron que la mayoría de los terapeutas ocupacionales evalúan los componentes ocupacionales de rutina/hábitos, roles, volición, tiempo libre e historia laboral en la etapa de ingreso a Centros de Tratamiento y Rehabilitación. Los resultados también revelaron una carencia de modelos y evaluaciones adecuadas y específicas desde la Terapia Ocupacional en el tema de estudio. Este estudio concluye en que existe una carencia de homogeneidad en el lenguaje, instrumentos de evaluación y los modelos utilizados entre Terapeutas Ocupacionales en los distintos Centros de Tratamiento y Rehabilitación.

This research topic is framed within the field of occupational therapy and problematic drug abuse. The purpose of this qualitative study is to explore what occupational components occupational therapists assess in the process of treatment and rehabilitation of problematic drug abuse. The study also explores the models and assessments used during this process. The participants were selected out of the list of Treatment and Rehabilitation Centers, that provides Occupational Therapy intervention in an Intensive Outpatient Program. This list was obtained from thedatabase of the National Council for Narcotics Control (CONACE). Data was collected through literature review on the topic and semi-structured interviews with seven Occupational Therapists with experience in the field of Drug Addiction Treatment and Rehabilitation. Theinterviews focused on the following topics: occupational components that are assessed for occupational therapists during the process of Treatment and Rehabilitation, models or theoretical frameworks and assessments used during this process and occupational components most affected. The results revealed that the majority of occupational therapists evaluate the occupational components of routine / habits, roles, volition, leisure and work history at the stage of admission to Treatment and Rehabilitation Centers. In addition, the results reveal a lack of appropriate and specific models andassessments from the occupational therapy perspective within the field of drug abuse. This study concludes that there is a lack of homogeneity in language, assessment tools and models used between the Occupational Therapists working in the Treatment and Rehabilitation Centers.

[Critical period of cortical plasticity]. / Períodos críticos de plasticidad cortical.

INTRODUCTION AND DEVELOPMENT: Alterations of sensory experience cause large-scale re-arrangements of cortical connectivity only early in life. After a critical period that roughly ends by puberty, comparable modifications requires more invasive manipulations, including deafferentation and cortical lesions. At a cellular level, the elementary mechanisms responsible for synaptic modification appear to be available throughout life. Thus, in adults, experience dependent plasticity might be constrained additional factors, like the maturation of inhibition or changes in the extra cellular matrix. Such view is consistent with a limited, but not absent, modifiability of adult cortical circuits. This view also has interesting therapeutical implications. CONCLUSION: In this scenario, manipulation of these limiting factors, for example reducing synaptic inhibition, might be a useful strategy to enhance plasticity and to restore function in the adult cortex.

Períodos críticos de plasticidad cortical / Critical period of cortical plasticity

Introducción y desarrollo. Las alteraciones de la experiencia sensorial causan reordenamientos a gran escala de la conectividad cortical sólo en etapas tempranas de la vida. Tras un período crítico que aproximadamente termina en la pubertad, modificaciones similares requieren manipulaciones más invasivas, entre ellas deaferentación y lesiones corticales. En el ámbito celular, los mecanismos elementales responsables de la modificación sináptica parecen estar disponibles a lo largo de toda la vida. Por consiguiente, en adultos, la plasticidad dependiente de la experiencia podría estar limitada a factores adicionales, como la maduración de la inhibición o cambios en la matriz extracelular. Esta visión es compatible con una capacidad de modificación limitada, pero no ausente, de los circuitos corticales adultos. Esta idea también tiene interesantes implicaciones terapéuticas. Conclusión. En este escenario, la manipulación de estos factores limitantes, como la reducción de la inhibición sináptica, podría ser una estrategia útil para incrementar la plasticidad en la corteza adulta (AU)

Introduction and development. Alterations of sensory experience cause large-scale re-arrangements of cortical connectivity only early in life. After a critical period that roughly ends by puberty, comparable modifications requires more invasive manipulations, including deafferentation and cortical lesions. At a cellular level, the elementary mechanisms responsible for synaptic modification appear to be available throughout life. Thus, in adults, experience dependent plasticity might be constrained additional factors, like the maturation of inhibition or changes in the extra cellular matrix. Such view is consistent with a limited, but not absent, modifiability of adult cortical circuits. This view also has interesting therapeutical implications. Conclusion. In this scenario, manipulation of these limiting factors, for example reducing synaptic inhibition, might be a useful strategy to enhance plasticity and to restore function in the adult cortex (AU)

Developmental inhibitory gate controls the relay of activity to the superficial layers of the visual cortex.

A developmental reduction in the radial transmission of synaptic activity has been proposed to underlie the end of the critical period for experience-dependent modification in layers II/III of the visual cortex. Using paired-pulse stimulation, we investigated in visual cortical slices how the propagation of synaptic activity to the superficial layers changes during development and how this process is affected by sensory experience. The results can be summarized as follows. (1) Layers II/III responses to repetitive stimulation of the white matter become increasingly depressed between the third and sixth week of postnatal development, a time course that parallels the end of the critical period. (2) Paired-pulse depression is reduced after dark rearing and also by blocking inhibitory synaptic transmission. (3) Paired-pulse depression and its regulation by age and sensory experience is more pronounced when stimulation is applied to the white matter than when applied to layer IV. Together, these results are consistent with the idea that the maturation of intracortical inhibition reduces the capability of the cortex to relay incoming high-frequency patterns of activity to the supragranular layers.

Spatiotemporal profile of synaptic activation produced by the electrical and visual stimulation of retinal inputs to the optic tectum: a current source density analysis in the pigeon (Columba livia).

The optic tectum of the pigeon is a highly organized, multilayered structure that receives a massive polystratified afference of at least five different populations of retinal ganglion cells and gives rise to various anatomically segregated efferent systems. The synaptic organization of retino-tectal circuitry is, at present, mostly unknown. To investigate the spatiotemporal profile of synaptic activation produced by differential (electrical and visual) stimulation of the retinal inputs, we performed a high-spatial-resolution current source density analysis in the optic tectum of the anaesthetized pigeon. Electrical stimuli consisted of brief pulses of different durations applied to the optic nerve head, while visual stimuli consisted of light flashes of different intensities. Electrical stimulation generated sinks confined to retinorecipient layers. The temporal structure, spatial location and thresholds of these sinks indicated that they are all due to primary tectal synapses of retinal fibers with different conduction velocities. Sinks evoked by the fastest retinal axons were more superficially located than sinks produced by slower retinal fibers. Visual stimulation, on the other hand, resulted in a more complex pattern of current sinks, with various sinks located in the retinorecipient layers and also well below. Visual stimulation induced action potentials at superficial as well as deep tectal levels. We conclude that electrical stimulation activates most of the populations of ganglion cells as well as their primary tectal synapses, but is unable to elicit a significant activation of secondary tectal synapses. Visual stimulation, on the contrary, activates just some of the incoming retinal populations, but in a way that produces noticeable secondary activation of intratectal circuits. Laminar segregation of retinally evoked tectal activity, as reported here, has also been found in other vertebrates. Similarities and differences with previous studies are discussed.

Modulation of long-term synaptic depression in visual cortex by acetylcholine and norepinephrine.

In a slice preparation of rat visual cortex, we discovered that paired-pulse stimulation (PPS) elicits a form of homosynaptic long-term depression (LTD) in the superficial layers when carbachol (CCh) or norepinephrine (NE) is applied concurrently. PPS by itself, or CCh and NE in the absence of synaptic stimulation, produced no lasting change. The LTD induced by PPS in the presence of NE or CCh is of comparable magnitude with that obtained with prolonged low-frequency stimulation (LFS) but requires far fewer stimulation pulses (40 vs 900). The cholinergic facilitation of LTD was blocked by atropine and pirenzepine, suggesting involvement of M1 receptors. The noradrenergic facilitation of LTD was blocked by urapidil and was mimicked by methoxamine, suggesting involvement of alpha1 receptors. beta receptor agonists and antagonists were without effect. Induction of LTD by PPS was inhibited by NMDA receptor blockers (completely in the case of NE; partially in the case of CCh), suggesting that one action of the modulators is to control the gain of NMDA receptor-dependent homosynaptic LTD in visual cortex. We propose that this is a mechanism by which cholinergic and noradrenergic inputs to the neocortex modulate naturally occurring receptive field plasticity.

Potency control of foot-and-mouth disease vaccine in cattle. Comparison of the 50% protective dose and the protection against generalization.

Potency tests of a total of 658 foot-and-mouth disease (FMD) vaccine batches by bovine protective dose (PD50) showed that 22% of the tests did not follow the expected theoretical model and the results could not be interpreted because of the lack of a dose-response relationship. The protection against generalization (PG) method, using undiluted vaccine, proved to be highly reliable from the analysis of the results of 65 replicate potency tests of three hydroxide-saponin (HS) vaccines and two oil-adjuvanted (OL) vaccines. The PG results were consistent in 64 out of the total of 65 tests. The data obtained indicated that, with regard to direct tests in cattle, the PG test is the preferred method for FMD vaccine potency control. This study also showed that the incorporation of a reference vaccine in routine potency tests is essential to ensure normality of the test system and that good quality HS and OL FMD vaccines may maintain immunogenic stability for at least 27 and 36 months, respectively, when stored at 2-8 degrees C.

Bilateral diaphragmatic paralysis complicating local cardiac hypothermia during open heart surgery.

Filling the pericardial sac with ice and saline during open heart surgery protects the myocardium during periods of ischemic arrest. Bilateral diaphragmatic paralysis complicated intense local hypothermia in five patients undergoing coronary artery bypass surgery. All complained of severe orthopnea, exertional dyspnea, insomnia, and excessive daytime somnolence. All exhibited paradoxic inward movement of the abdominal wall with inspiration. The diagnosis of bilateral diaphragmatic paralysis was confirmed with upright and supine spirometry and, in one patient, with transdiaphragmatic pressure measurements. Although paralysis has resolved in four patients, all experienced months of disabling impairment. One patient required four months of mechanical ventilatory support prior to her recovery. Alternative methods of intraoperative myocardial preservation that avoid this complication should be developed.

Alkaline phosphatase activity as a membrane marker for activated B cells.

Alkaline phosphatase activity was assayed by a microtiter assay (with p-nitrophenylphosphate used as substrate) in the plasma membrane of mouse spleen cells activated in vitro by the B cell mitogen LPS and the T cell-dependent B cell mitogen, PWM. No activity was detected in spleen cells cultured in the presence of the T cell mitogens PHA and Con A. This alkaline phosphatase activity was detected in the blast-enriched 30 to 40% fraction of discontinuous Percoll gradients in LPS-treated cultures, and the enzymatic activity assayed was susceptible to inhibition by the alkaline phosphatase inhibitors EDTA and L-phenylalanine. These data support the idea that the membrane alkaline phosphatase activity could be used as a marker for activated B cells.

Daily spirometric variability: normal subjects and subjects with chronic bronchitis with and without airflow obstruction.

To determine the daily variability of spirometry, we performed spirometry on five consecutive days on 15 normal subjects and on 24 patients with chronic bronchitis. The patients with chronic bronchitis were divided into the following two groups: 13 with chronic airflow obstruction (forced expiratory volume in 1 s [FEV1] 80%, FEV1/forced vital capacity [FVC] ratio less than 75%) and 11 without airflow obstruction (FEV1 and FVC greater than 80%0. We attempted to control most of the factors known to affect spirometric variability. Our results indicate that the day-to-day FEV1 has to change by 17% and the FCV by 15% in patients with airflow obstruction before the change should be considered significant. In patients with nonobstructive chronic bronchitis or in normal subjects, a greater than 5% change should occur in FEV1 and FVC before considering the change to be significant.

[Comparative study of the susceptibility of suckling and adult mice used for the isolation of rabies virus from the saliva of dogs with natural rabies]. / Estudo comparativo entre a susceptibilidade de camundongos lactentes e adultos para o isolamento de vírus rábico a partir da saliva de cães com raiva natural.

Forty two saliva samples from rabid dogs were examined by intracerebral inoculation of weanling and suckling mice. Although rabies virus assay were successful in all of the samples in both groups of mice used, a significant higher death proportion (p < 0.01) were observed in the suckling mice group.