Processamento de vitrocerâmicas a base de dissilicato de lítio com gradiente funcional de porosidade / Processing of glass-ceramic based of lithium disilicate with functional gradient of porosity

O desempenho das cerâmicas odontológicas é um aspecto bastante explorado na literatura, uma vez que o aprimoramento das suas características permite desenvolver materiais com maior longevidade. Trincas, delaminações, lascamentos e fraturas catastróficas são as falhas mais encontradas em restaurações cerâmicas. O objetivo dessa pesquisa foi conhecer o comportamento mecânico de coroas monolíticas gradadas e avaliar a possibilidade de produzir uma vitrocerâmica experimental a base de dissilicato de lítio com gradiente funcional de porosidade. Este trabalho foi dividido em duas partes: a primeira, teórico/computacional e a segunda, a fabricação do produto. 1) Através de software CAD foi modelado um molar inferior com preparo tradicional para coroa total e uma coroa total monolítica com camada de cimento resinoso entreposto. Quatro grupos foram compostos pela variação da composição das coroas totais: Coroa rígida (E=80 GPa), flexível (E=30 GPa), gradação bioinspirada (de 80 até 30 GPa) e gradação inversa (de 30 até 80 GPa). O modelo foi exportado para o software de análise. Os materiais foram considerados isotrópicos, linearmente elásticos e homogêneos, com contatos ideais. Uma força de 300N foi aplicada na face oclusal, a base do modelo foi fixada em todas as direções. A tensão máxima principal, tensão de Von-Mises e deslocamento foram utilizadas para observar o comportamento mecânico. 2) Uma mistura de óxidos foi homogeneizada e submetida à fusão. As fritas obtidas por resfriamento foram moídas e passaram por diferentes tratamentos térmicos, seguido das análises de DSC e DRX. Seis grupos experimentais foram obtidos: DL-E (vitrocerâmica densa a base de dissilicato de lítio simulando esmalte); DL-D (vitrocerâmica densa a base de dissilicato de lítio simulando dentina); DLGrad (vitrocerâmica gradada a base de dissilicato de lítio); YTZP-E (vitrocerâmica densa reforçada por YTZP simulando esmalte); YTZP-D (vitrocerâmica densa reforçada por YTZP simulando dentina); YGrad (vitrocerâmica gradada reforçada por YTZP). Suspensões aquosas contendo 23 e 30%-vol. de pó de vidro foram preparadas e submetidos à técnica de gel casting para formar um gradiente funcional. As vitrocerâmicas com e sem gradiente funcional de porosidade foram caracterizadas pelas técnicas de DRX, FEG, densidade e porosidade aparentes. Também foram realizados ensaios mecânicos de resistência à flexão biaxial e fractografia. Os resultados obtidos foram estatisticamente avaliados por Anova 1 fator e Tukey (p<0,05). As micrografias mostraram formação de gradiente funcional de porosidade apenas nas vitrocerâmicasa base de dissilicato de lítio. Não houve diferença entre as densidades de todos as vitrocerâmicas estudadas, porém YTZP-E, YTZP-D e YTZP-Grad apresentaram porosidade 10% maior do que as vitrocerâmicassem zircônia. Os defeitos críticos na superfície das vitrocerâmicas são semelhantes em todas condições estudadas, porém a aleatoriedade de poros internos das vitrocerâmicas contendo YTZP proporcionaram diminuição da resistência à flexão, com diferença estatisticamente significante em relação às vitrocerâmicas sem YTZP. Entre as vitrocerâmicas densas e gradadas não houve diferença na resistência à flexão. Conclui-se que a adição de zircônia em sistema a base de SiO2-Li2O alterou a temperatura de sinterização, o padrão de porosidade, a resistência flexural e comprometeu a formação do gradiente funcional de porosidade. O comportamento mecânico das vitrocerâmicas à base de dissilicato de lítio densas e gradadas são similares(AU)

The performance of dental ceramics is very explorated at literature, once the enhancement of yours features allow the development of materials with higher longevity. Cracks, delamination, chipping and catastrophic fracture are the faillures most finds at ceramics restorations. The aim of this research was knew the mechanical behavior of monolithics graded crows and it was evaluated the possibility to produce a glass ceramic based of lithium disilicate with gradient of porosity. This research was divided into two parts: the first one, theoretical computational and the second, the manufacturing product. 1) Using a CAD software, a lower molar received a full-crown preparation. The monolithic crown was modeled with a resin cement layer of 0.1 mm. Four groups were distributed according to the full crown elastic modulus (E):(a)Bioinspired crown with regressive elastic gradation (from 80 to 30 GPa); (b) Crown with regressive elastic gradation (from 30 to 80 GPa); (c) Rigid crowns and (d) Flexible crown. The model was exported to the analysis software and meshed into 385,240 tetrahedral elements and 696,310 nodes. Materials were considered isotropic, linearly elastic, and homogeneous, with ideal contacts. A 300-N load was applied at the occlusal surface and the base of the model was fixed in all directions. The results were required in Maximum principal stress, Von-Mises Stress and Displacement. 2) A mixture of oxides was homogenized and it was melted at fusion. The glass frits get by cooling were grinded and passed through heat treatment accordin to CSD and RXD. Six groups were obtained: DL-E (glass ceramic dense based of lithium disilicate simulating enamel); DL-D (glass ceramic dense based of lithium disilicate simulating dentin); DL-Grad (glass ceramic graded based of lithium disilicate); YTZP-E (glass ceramic dense reforced by YTZP simulating enamel); YTZP-D (glass ceramic dense reforced by YTZP simulating dentin); YTZP-Grad (glass ceramic graded and reforced by YTZP). Twenty-three and 40% of glass powder were prepared through dispersion water and it was submitted for techinique of gel casting to form functional gradient. The samples with and without functional gradient of porosity were characterized by RXD, FEG, density of all the groups, however YTZP-E, YTZP-D and YTZP-Grad showed porosity 10% greater the groups without zirconia. The critical flaw at surface of the ceramics were similar to the groups, however the random of internal pores at groups with YTZP get the flexural strength lower, with statistical difference with the groups without YTZP. Among the dense and graded groups were not statistical differences at flexural strength. It concluded that add of zirconia at ceramic system based of SiO2-Li2O changed the temperature of sintering, the standard of porosity, flexural strength and compromised the development of functional gradient of porosity. The mechanical behavior of ceramics based at lithium disilicate dense and graded were similar(AU)

Compromiso de conciencia secundario a intoxicación por litio: reporte de un caso / Commitment of conscience secondary to lithium intoxication: case report

INTRODUCCIÓN: La intoxicación por litio (IL) es potencialmente grave. Destacan manifestaciones neurológicas, tales como deterioro cognitivo, síndrome cerebeloso y compromiso de conciencia (CC). En la literatura se han descrito secuelas permanentes secundarias a la IL, siendo importante el manejo precoz para prevenir una evolución tórpida de este cuadro. PRESENTACIÓN DEL CASO: Paciente de sexo femenino de 77 años con antecedentes de Trastorno Afectivo Bipolar (TAB), en tratamiento con Litio, inició cuadro de 5 días de evolución caracterizado por bradipsiquia, compromiso del estado general (CEG) y disminución de fuerza en extremidades inferiores. Evaluada por Neurología, se descartó patología cerebrovascular e infecciosa intercurrente, se midió litemia que resultó alterada. Se diagnosticó CC secundario a IL. Se indicó suspensión de fármaco y manejo de balance hidroelectrolítico. Evolucionó con daño neurológico de pronóstico incierto y fue dada de alta por Neurología. DISCUSIÓN: La intoxicación por litio debe sospecharse en cualquier paciente con alteración del estado de conciencia basal, que sea usuario de este medicamento. Pacientes que presentan IL requieren hospitalización para manejo de fluidos y electrolitos, monitorizando función renal y litemia. A nivel del sistema nervioso central (SNC) la IL puede dejar secuelas irreversibles, por lo que se recomienda un seguimiento regular de aquellos pacientes que sean usuarios de este medicamento, para evitar un deterioro clínico secundario a una intoxicación.

INTRODUCTION: (LI) can be potentially serious. Includes neurological manifestations such as cognitive impairment, cerebellar syndrome and compromise of consciousness (CC). In the literature have been described permanent sequelae secondary to intoxication by this drug, early management is important to prevent an undesirable evolution of this medical condition. CASE REPORT: 77-year-old female patient with a history of Bipolar Affective Disorder, under treatment with Lithium, began a 5-day history of bradypsychia, compromise of the general state and decrease strength in lower extremities. Evaluated by Neurology, ruled out cerebrovascular and infectious pathologies. Plasmatic lithium levels were obtained in altered range. CC secondary to LI was diagnosed. Drug suspension, fluid and electrolyte balance management were indicated. She evolved with neurological damage of uncertain prognosis and discharged from hospital. DISCUSSION: LI should be suspected in any patient with altered baseline consciousness, who is a user of this medication. Patients requires admission for fluid and electrolyte management, monitoring of renal function and plasmatic lithium levels. At the level of the central nervous system (CNS) IL can leave irreversible sequels, so it is recommended a regular monitoring of patients who are users of this drug, to avoid clinical deterioration secondary to intoxication.

Monitoreo del litio / Lithium monitoring

Objetivo: El litio continúa siendo un fármaco de primera línea para el tratamiento de las distintas fases y tipos de enfermedad bipolar, muy posiblemente debido a su eficacia. El monitoreo es necesario para su prescripción segura debido a su rango terapéutico estrecho, su perfil de eventos adversos y su uso durante extensos períodos de tiempo. Se realiza una revisión bibliográfica sobre el monitoreo del litio y las recomendaciones que de allí se derivan para su aplicación en el ámbito de la asistencia clínica de pacientes con patología bipolar. Método: Búsqueda en biblioteca electrónica (medline) desde 1998 hasta la actualidad de los siguientes términos: monitoreo litio, estudio clínico SILENT (neurotoxicidad inducida por litio), tiroides, tiroiditis de Hashimoto, encefalopatía de Hashimoto y litio, interacciones farmacológicas y eventos adversos. Fueron consultadas la guía de tratamiento canadiense, Canadian Network for Mood and Anxiety (CANMAT actualización 2009) (1)), la National Institute for Health and Clinical Excellence (NICE) (2), aprobaciones de la FDA (Food and Drug Administation, EE.UU.) y la International Society for Bipolar Disorders (ISBD). Resultados: El monitoreo de la concentración plasmática de litio estaría indicado cada 3 meses, o cada cambio de dosis o ante comorbilidad con otra enfermedad (2). Evitar la intoxicación aguda para disminuir el riesgo renal y la neurotoxicidad. Es conveniente tener en cuenta el tiempo de prescripción del fármaco y la edad del paciente, debido a la declinación de la función renal a partir de los 50 años. A los 5 años el daño estructural en el túbulo renal puede convertir a la diabetes insípida en irreversible. A los 10 años la prevalencia de falla renal progresiva ocurre en aproximadamente el 20 % de los pacientes (3, 4). La evaluación clínica del paciente es lo que permite hacer un diagnóstico precoz de neurotoxicidad inducida por litio, los factores de riesgo requieren mayor alerta: edad avanzada...

Objective: Lithium remains a first-line drug for the treatment of the different phases and types of bipolar disorder, most likely due to its effectiveness despite its adverse events. Monitoring is necessary for the safe prescription of lithium, given its narraw therapeutic range, the adverse event profile, and its use for extended periods of time. We revise the literature on lithium monitoring and the recommendations that derive from it, for use in the field of the clinical care of patients with bipolar disorder. Method: From 1998 to the present i serched the following terms in Medline: lithium monitoring, SILENT (lithium-induced neurotoxicity), thyroid, Hashimoto's thyroiditis, Hashimoto's encephalopathy and lithium, drug interactions and adverse events. We consulted the Canadian treatment guidelines, the Canadian Network for Mood and Anxiety (update CANMAT 2009), the National Institute for Health and Clinical Excellence (NICE) and the approvals of the FDA (Food and Drug Administration, USA, and the International Society for Bipolar Disorders (ISBD). Results: the monitoring of lilthium plasma concentration would be indicated every 3 months, or every dose change, or when there is comorbidity with other diseases. It is useful to prevent acute toxicity in order to reduce kidney risk and neurotoxicity. The length of prescription and the patients's age should be taken into account, due to the decline in the renal function past the age of 50. At 5 years, the structural damage in the renal tubule can turn diabetes from insipid to irreversible. At 10 years, progressive renal failure occurs in approximately 20 % of the patients. The clinical evaluation of the patient is what allows an early diagnosis of lithium-induced neurotoxicity; the risk factors demand a higher alert: advanced age, prior neurological disease, medical...

Estudio descriptivo del uso de antidepresivos en pacientes bipolares en una unidad de trastornos afectivos bipolares en el sistema público / Descriptive study of the use of antidepressants in bipolar patients in an affective disorders unit in the public system

Introduction: the use of antidepressants in the depressive phase of the bipolar disorder is controversial. Currently there are two conflicting positions, the purists are inclined to avoid them in a hospital in the public health system. Method: a descriptive study of cross section. Cards of 81 patients with diagnosis of bipolar disorder from “las Higueras” Hospital in Talcahuano were analized, we obtained different information such as sex, subtype of bipolar disorder, suicide attepts and indication of psychotropic drugs like mood stabilizers, antidepressants, antipsychotics and anxiolytics. For the analysis of the information obtained we utilized the program SPSS 17.0 using the x2 test and descriptive statistics. The results are de followings: 54.3 percent have a diagnosis of bipolar affective disorder type I and 45.7 percent has type II. 50.6 percent of all patients were using some type of antidepressant. From that group, 65.7 percent had at least one suicide attempt, while 37.2 percent never had. This turned out to be statistically significant. In patients who had attempted suicide there was no significant difference between patients who were using lithium fro those who were not. Discussion: half of the studied patients were receiving some type of antidepressants, which allows us to conclude that in our hospital, there is a liberal position in relation to its use in spite of the medical personnel being trained in the American position. Lithium was the most suitable stabilizer; though there was no effectiveness against suicide attempt.

Introducción: el uso de antidepresivos en la fase depresiva bipolar es controversial. Actualmente existen dos posturas, la purista proclive a evitarlos y la liberal que favorece las ventajas en su uso. Nuestro objetivo es dilucidar cuál de ellas prevalece en un hospital del sistema público de salud. Método: estudio descriptivo de corte transversal. Se analizaron fichas de 81 pacientes con diagnóstico de trastorno bipolar del Hospital Higueras Talcahuano, obteniéndose variables como sexo, subtipo de trastorno bipolar, edad de inicio, intentos suicidas, hospitalizaciones e indicación de psicofármacos, diferenciado estabilizadores del ánimo, antidepresivos, antipsicóticos y ansiolíticos. Para el análisis se usó programa SPSS 17.0, utilizando las pruebas de x2 y estadísticos descriptivos. Resultados: un 54.3 por ciento presentan diagnóstico de trastorno afectivo bipolar (TAB) tipo I y un 45.7 por ciento TAB tipo II. Un 50.6 por ciento del total de pacientes usaban algún tipo de antidepresivo. Un 65.7 por ciento presentaron al menos un intento suicida y un 37.2 por ciento nunca lo presentaron. Estos resultados fueron estadísticamente significativos. En los que presentaron intento suicida, no hubo diferencias significativas en cuanto al empleo de litio. Discusión: la mitad de los pacientes estudiados recibían algún tipo de antidepresivo, lo que permite concluir que en esta establecimiento se mantendría una postura liberal en relación a su uso a pesar de capacitar al personal médico en la postura americana. El litio fue el estabilizador más indicado, sin evidenciarse eficacia antisuicida.

Avaliação da dose no reto em pacientes submetidas a braquiterapia de alta taxa de dose para o tratamento do câncer do colo uterino / Rectal dose assessment in patients submitted to high-dose-rate brachytherapy for uterine cervix cancer

OBJETIVO: O objetivo deste trabalho foi desenvolver um sistema dosimétrico termoluminescente capaz de avaliar as doses administradas ao reto de pacientes submetidas a braquiterapia de alta taxa de dose para o tratamento do câncer do colo uterino. MATERIAIS E MÉTODOS: O material termoluminescente utilizado para a avaliação da dose no reto foi o LiF:Mg,Ti,Na na forma de pó. O pó foi separado em pequenas porções de 34 mg, que foram acomodadas em um tubo capilar. Este tubo foi colocado em uma sonda retal, que era introduzida no reto da paciente. RESULTADOS: As doses administradas ao reto de seis pacientes submetidas a braquiterapia de alta taxa de dose para o tratamento do câncer do colo uterino foram avaliadas com dosímetros termoluminescentes e apresentaram boa concordância com os valores planejados, com base em duas radiografias ortogonais da paciente, imagens ântero-posterior e lateral. CONCLUSÃO: O sistema de dosimetria termoluminescente utilizado no presente trabalho é simples e de fácil utilização quando comparado a outros métodos de dosimetria do reto. Ele mostrou-se eficiente na avaliação da dose no reto de pacientes submetidas a braquiterapia de alta taxa de dose para o tratamento do câncer do colo uterino.

OBJECTIVE: The present study was aimed at developing a thermoluminescent dosimetric system capable of assessing the doses delivered to the rectum of patients submitted to high-dose-rate brachytherapy for uterine cervix cancer. MATERIALS AND METHODS: LiF:Mg,Ti,Na powder was the thermoluminescent material utilized for evaluating the rectal dose. The powder was divided into small portions (34 mg) which were accommodated in a capillary tube. This tube was placed into a rectal probe that was introduced into the patient's rectum. RESULTS: The doses delivered to the rectum of six patients submitted to high-dose-rate brachytherapy for uterine cervix cancer evaluated by means of thermoluminescent dosimeters presented a good agreement with the planned values based on two orthogonal (anteroposterior and lateral) radiographic images of the patients. CONCLUSION: The thermoluminescent dosimetric system developed in the present study is simple and easy to be utilized as compared to other rectal dosimetry methods. The system has shown to be effective in the evaluation of rectal doses in patients submitted to high-dose-rate brachytherapy for uterine cervix cancer.

Appropriateness of therapeutic drug monitoring for lithium.

OBJECTIVE: Evaluate the appropriateness of therapeutic drug monitoring (TDM) for lithium. MATERIAL AND METHOD: A retrospective chart review of all patients who received lithium for treatment of psychiatric disorders between January 2004 and October 2005 was done. The present study was investigated in a psychiatric hospital in Thailand Based on detailed chart review, the appropriateness of TDM utilization comprised of three aspects, i.e., the indication of TDM request, the time of blood sample taking in relation to the medication process, and the clinical applications of the reported serum lithium levels, were evaluated. The Morecambe Bay Shared Care Guideline 2003 was modified and used as criteria for evaluation. Altogether 91 serum lithium samples were measured among 60 patients. RESULT: In 66 (72.5%) of requests, clear indications for lithium TDM were recorded i.e., initiation therapy 41.8%, suspected toxicity 15.4%, patient compliance assessment 5.5%, after regimen changes 5.5%, and therapeutic failure 4.4%. Routine tests without specified indications were found in the remainder (27.5%), all were in-patients, which pointed to potentially redundant use. The time of sample taking was recorded in 37 (40.6%) of blood samples, all were taken from in-patients, after steady state had been reached. These data for out-patients were not recorded, except one noted that blood sample was drawn after the patient had not received lithium for four days. Serum lithium levels were reported in 83 (91.2%) samples. Of these, 37 (44.6%) were out of therapeutic range, and only 12 required dosage alterations. The evaluation demonstrated somewhat inappropriate use of reported lithium levels. Dose changes were done in some patients who required dosage adjustment. Among 14 toxicity-suspected patients, nine actually had serum lithium levels exceeding the therapeutic range. Of these, only one patient was subsequently switched to a reduced dose, three patients were discontinued while five patients were prescribed the pre-TDM doses. Similarly, in five toxicity-suspected patients whose serum lithium levels were below therapeutic range, lithium was discontinued in three patients and no dosage alteration, which was considerably acceptable, in two patients. The doses were increased in three out offour inadequately controlled patients whose serum lithium was lower than the therapeutic range. Overall, in only 33 (36.3%) requests was TDM performed appropriately according to the indication, sampling time and subsequent dose adjustment. CONCLUSION: The findings indicate the need to improve the utilization of TDM for lithium. Education for hospital personnel on appropriateness of serum sample collection, interpretation, and proper use of serum drug levels is encouraged. Development of a request form containing essential data, such as indication for TDM, current drug dosing regimen, time of last dose, patient compliance, test results and interpretations and clinical decision made, can help optimize TDM use and reduce unnecessary costs.

Effect of nimesulide co-administration on pharmacokinetics of lithium.

In a crossover study, lithium was given orally at a dose of 56 mg/kg, prepared as suspension (0.5%) in carboxymethyl cellulose (CMC) and blood samples (1 ml) collected after 0-24 hr after drug administration. After a washout period of two weeks, nimesulide (10 mg/kg) was administered alongwith lithium (56 mg/kg) and blood samples were drawn at the same time intervals (0-24 hr) after drug administration. Plasma was separated and assayed for lithium by M 654 Na+/K+/Li+ analyzer and various pharmacokinetic parameters were calculated. C(max), K(el), t(1/2el) and AUC(0-alpha) of lithium were significantly increased when nimesulide was administered along with lithium as compared to control group.

Tratamiento de la enfermedad bipolar durante el embarazo y puerperio: caso clínico / Treatment of a pregnant patient with a bipolar disorder: clinical case

We report a 37 years old woman with a severe bipolar disorder, that became pregnant during treatment with lithium. The patient and her family were informed about the 0.05-0.1 percent risk of cardiac malformations of the newborn, but decided to maintain her pregnancy and not to discontinue the use of lithium, fearing a relapse of her psychiatric ailment. She continued under medical surveillance and had a normal delivery, but no breast feeding was allowed

Lítio, Carbamazepina e Acido Valpróico: eficácia na fase de manutençäo / Lithium, carbamazepine and valproate: efficacy in the prophylaxis of bipolar disorder

Neste artigo, foi feita uma revis

Monitoreo terapéutico del litio

El litio es un fármaco de elección para el tratamiento de la manía y para el mantenimiento a largo plazo en la prevención de las crisis maníacas o depresivas del trastorno bipolar. Un conocimiento profundo del litio es necesario para alcanzar una utilización más segura y efectiva. Es un fármaco que debe ser utilizado con mucha precaución debido a su estrecha ventana terapéutica y la letalidad de la toxicidad relacionada con el mismo. Los pacientes deben ser evaluados clínica y paraclínicamente antes de iniciar la terapia con litio. Las interacciones farmacológicas deben ser tenidas presentes y se recomienda que la litemia, función tiroidea y función renal deben ser evaluadas mediante el laboratorio en asocio con un seguimiento clínico estricto. Las muestras de sangre para efectuar el monitoreo deben ser tomadas luego de cuatro días de estar tomando una dosis constante, doce horas después de la dosis de la noche y justo antes de tomar la de la mañana.

Drogas psicotrópicas e coraçäo / Psychotropic drugs and the heart

A moderna Psicofarmacoterapia teve início na década de 1960 e revolucionou o tratamento das doenças mentais. De modo sucessivo e, principalmente no início, empírico, antidepressivos como o diazepam, além do lítio e da carbamazepina foram sendo lançados. Muitas dessas drogas, como os antidepressivos tricíclicos, provocam, mesmo em doses terapêuticas, importantes açöes cardiológicas; eles também interagem, farmacoldinâmica ou farmacocineticamente, com medicamentos usados em Cardiologia. Neste artigo, säo abordados os principais efeitos cardiológicos diretos ou indiretos dos psicofármacos usados na terapêutica psiquiátrica.

Chronic but not acute Li+ treatment prevents behavioral depression in rats

The effect of lithium administration on the learned hellessness model of depression was investigated. Female Wistar rats (190-210g) received either tap water alone (N=156) or 20 mM LiCL, provided chronically (30 days; N = 127) or acutely (5 days; N = 22), in the drinking water. Three days before the end od treatment, each group was divided into two subgroups which received either inescapable shock (IS) or no shock (NS) treatment in shuttle boxes. All groups were subsequenty submitted to an escape test on the following day and then sacrificed one day after the escape test, when blood samples were taken to measure serum Li+, Na+ and K+ concentrations by flame photometry. There were no significant differences in serum Na+ amongst the 4 groups. chronically treated NS and IS rats both presented an increase in serum K+ compared to the control rats. The IS and not the NS chronically treated rats presented increased serum Li+ levels which cannot be accounted for in terms of differences in Li+ intake. The IS group treated chronically with lithium had a better escape performance than the IS group receiving either tap water or acute Li+ administration. We conclude that chronic but not acute Li+ treatment at a serum level within the prophylactic range (0,5 mEq) is able to prevent learned helplessness in the rat. These results agree with the data obtained in clinical practice indicating that li+ is only effective after chronic administration and that Li+ - induced hyperkalemia is a side effect

Lithium treatment prolongs shock-induced hypoalgesia

We have investigated the effect of chronic lithium (Li+) treatment on stress-induced hypoalgesia, a phenomenon known to be dependent on the activation and sensitization of the central opioid system. Adult female Wistar rats received either 20 mM LiCl in the drinking water (serum level of 0.5 mEq/l,N = 110) or tap water (controls N = 113) for 28 days. The rats were divided into three subgroups and were trained either by receiving 60 inescapable 1-mA footshocks (IS) while yoked to a escapable (ES) group, or by confinement (NS) to the shock box. As a control for the activation of the opioid system, we included rats injected with 0.9 percent saline (N = 24) or morphine (4 mg/kg, sc, N =20) before confinement. Twenty-four hours later, the rats (N = 187) were either submitted to five inescapable (1 s,0.6 mA) footshocks (shock reexposure) or received no shocks over the same period (N = 80). The pain threshold was estimated using a tail-flick apparatus after the training session and immediately after the shock reesposure. ANOVA followed by duncan's test indicated that hypoalgesia was produced soon after the training session in the morphine and shocked groups and persisted in the Li+-IS group for up to three days. Hypoalgesia was reinstated in the control IS and morphine groups by reexposure to the shochs, but was not modified in the Li+-IS groups. We conclude that Li+ treatment prolongs the hypoalgesia induced by inescapable shocks

Contratransporte sodio/litio en los globulos rojos, hipertensión arterial y nefropatía en pacientes con diabetes mellitus insulino-dependiente / Contratransport sodio/litio in red cells, arterial hypertension and diabetic nephropathy in patients insulin-dependent diabetes mellitus

El objetivo de este trabajo fue el tratar de dilucidar si una actividad aumentada del sistema de transporte transmembrana sodio/litio (Na+/Li+) en los glóbulos rojos (GR) de pacientes con diabetes mellitus insulino dependientes (DMID) desempeña un papel en los mecanismos de enfermedad del diabético (Nefropatía Diabética; ND) y su relación con hipertensión arterial (HTA) o si se trata de una alteración inherente al estado diabético. Para ello se evaluaron 27 pacientes con DMID y 15 controles sanos a quienes se le practicaron entre otros exámenes: hemoglobina glicosilada, microalbuminuria, funcionalismo renal (FR), perfil lipídico y medida de la actividad Na+/Li+ en las membranas de los GR. Como resultado se obtuvo un aumento significativo en los pacientes diabéticos de la actividad del contratransporte (CTr) Na+/Li+ al compararlo con controles, sin correlación directa con alteraciones de la FR, HTA y retinopatía pero si con las alteraciones del perfil lipídico. Concluimos, en que una predisposición genética a HTA esencial parece no jugar un papel importante en la patogenia de la ND, no debiéndose por tanto a las alteraciones del CTr Na+/Li+ como marcador precoz de enfermedad renal; la microalbuminuria sigue siendo el mejor marcador temprano de esta patología. La relación entre alteraciones del CTr Na+/Li+ y las del perfil lipídico observadas en este trabajo sugieren modificaciones de este y otros sistemas transmembrana en diabéticos

Aspectos neurobiológicos de la conducta suicida: prevención farmacológica del suicidio / Neurobiological aspects of suicidal behaviour: pharmacological prevention of suicide

El estudio de los aspectos neurobiológicos de la conducta suicida se ha desarrollado desde la década del 70. Asberg (5) encontró en un subgrupo de pacientes que habían cometido más intentos de suicidio y de manera más violenta una concentración de ácido 5 hidroxindolacético (5-H.I.I.A.), en el líquido cefalorraquídeo más baja, que la encontrada en un subgrupo de pacientes que habían realizado intentos de suicidio menos violentos cuya concentración de 5-H.I.I.A. era normal. Asimismo, estudios realizados en personas con conducta agresiva demuestran que éstas presentan una concentración de 5-H.I.I.A., bajo, grupo que debe ser considerado como de alto riesgo por su proclividad a presentar conductas peligrosas para la vida. Brown (11) ha sugerido que una concentración de 5-H.I.I.A., en líquido cefalorraquídeo menor que 92,5 nmoles/t debería alertar al clínico, puesto que en estos pacientes habría una mayor propensión a presentar intentos de suicidio y mayor agresividad interpersonal. En cuanto a la prevención farmacológica del suicidio se menciona el uso de antidepresivos serotoninérgivos como mianserina; neurolépticos como trifluoperazina y decanoato de flufenazina y de los estabilizadores del ánimo, litio y carbamazepina. El litio es conocido por su capacidad de inhibir el impulso auto y heteroagresivo (12), lo cual es concordante con la disminución de la mortalidad en un grupo de 812 pacientes con trastornos del ánimo tratados con litio (25) en comparación con la mortalidad esperada por tablas de vida. En consecuencia el litio puede ser considerado al menos en este subgrupo de pacientes como un agente profiláctico de la conducta suicida

La depresión bipolar en la adolescencia: epidemiología, cuadro clínico y tratamiento / Bipolar depression in adolescence: epidemiology, clinical manifestations and treatment

En este trabajo se revisa la epidemiología, el cuadro clínico, el diagnóstico diferencial y el tratamiento farmacológico del Trastorno Bipolar del estado de ánimo en la adolescencia. Se presenta el caso clínico de un paciente de 17 años, con una Depresión Bipolar, diagnosticado de acuerdo al D.S.M. III, quien se encuentra en control ambulatorio en el Policlínico de Enfermedades Afectivas del Instituto Psiquiátrico José Horwitz de Santiago, en tratamiento profiláctico con litio y carbamazepina. Su evolución clínica ha sido graficada en una "hoja de vida", donde se han correlacionado los eventos de vida, sucesivos diagnósticos, y tratamientos. Se concluye que la irritabilidad, hiperactividad y el trastorno conductual en niños pueden ser precursores del Trastorno Bipolar. Si a lo anterior se suma el antecedente familiar de depresión bipolar o hipomanía, frente a un adolescente con una depresión, el clínico debe considerar el diagnóstico de Trastorno Bipolar

Orientacao basica para tratamento e profilaxia de doencas afetivas com litio / Orientation basic for treatment and prophylaxis of affective diseases with lithium

O carater cronico-recidivante dos disturbios afetivos dificulta sobremaneira seu tratamento e profilaxia. O emprego de sais de litio para este fim vem sendo praticado cientificamente ha mais de trinta anos, com resultados que comprovam seus beneficios e colocam a litioterapia entre as principais possibilidades psicofarmacoterapeuticas existentes. A litioterapia esta indicada em doencas afetivas mono e bipolares, e na psicose esquizoafetiva, como profilatico, e em estados maniacos agudos, ou seja, atua sobre todo o espectro dos disturbios afetivos graves, ocupando a posicao de medicamento principal a longo prazo, ao qual, segundo indicacoes clinicas, outros medicamentos, como neurolepticos ou antidepressivos, podem ser adicionados. A uma introducao historica da aplicacao dos sais de litio, seguem orientacoes gerais para o uso do medicamento, como indicacoes, regimes, contra-indicacoes, controle e tempo de tratamento