The absence of brain-specific link protein Bral2 in perineuronal nets hampers auditory temporal resolution and neural adaptation in mice.

Brain-specific link protein Bral2 represents a substantial component of perineuronal nets (PNNs) enwrapping neurons in the central nervous system. To elucidate the role of Bral2 in auditory signal processing, the hearing function in knockout Bral2(-/-) (KO) mice was investigated using behavioral and electrophysiological methods and compared with wild type Bral2(+/+) (WT) mice. The amplitudes of the acoustic startle reflex (ASR) and the efficiency of the prepulse inhibition of ASR (PPI of ASR), produced by prepulse noise stimulus or gap in continuous noise, was similar in 2-week-old WT and KO mice. Over the 2-month postnatal period the increase of ASR amplitudes was significantly more evident in WT mice than in KO mice. The efficiency of the PPI of ASR significantly increased in the 2-month postnatal period in WT mice, whereas in KO mice the PPI efficiency did not change. Hearing thresholds in 2-month-old WT mice, based on the auditory brainstem response (ABR) recordings, were significantly lower at high frequencies than in KO mice. However, amplitudes and peak latencies of individual waves of click-evoked ABR did not differ significantly between WT and KO mice. Temporal resolution and neural adaptation were significantly better in 2-month-old WT mice than in age-matched KO mice. These results support a hypothesis that the absence of perineuronal net formation at the end of the developmental period in the KO mice results in higher hearing threshold at high frequencies and weaker temporal resolution ability in adult KO animals compared to WT mice.

[Design and validation of a classification system for assessing the degree of disability of patients with amyotrophic lateral sclerosis]. / Diseño y validacion de un sistema de clasificacion para evaluar el grado de discapacidad de los pacientes con esclerosis lateral amiotrofica.

INTRODUCTION: Currently there is no system of classification validated and commonly used to allow staging the severity of amyotrophic lateral sclerosis. PATIENTS AND METHODS: Based on the ALSFRS-R, four domains were established (bulbar, manual skills, gross motor function and respiratory function). Each item had a 0 score if the rate was >= 3 (independence) or 1 if the rate was < 3 (dependence). The functional classification scale was defined as follows: stage 1, without a loss of independence on any domain, until stage 5, with loss of independence in all four domains. This classification is correlated with the need of external support, quality of life with the application of the ALSAQ-40 scale, muscle strength and survival. RESULTS: From a total of 244 patients, 14.3% were in stage 1, 23.8% in stage 2, 21.3% in stage 3, 19.3% in stage 4 and 21.3% in stage 5. Muscle strength and quality of life were inversely proportional to the stage of the disease, while the need for external aids is directly related to the increase in disease stages 1 to 5 (p < 0.012). Increased survival of patients was found in stages 1 and 2 with respect to those in stages 3, 4 and 5 (p = 0.004). CONCLUSION: The proposed classification system is easy to apply and correlates well with the patient's clinical, quality of life, resource requirements and survival.

TITLE: Diseño y validacion de un sistema de clasificacion para evaluar el grado de discapacidad de los pacientes con esclerosis lateral amiotrofica.Introduccion. Actualmente no existe un sistema de clasificacion validado y de uso comun para estadificar la gravedad de la esclerosis lateral amiotrofica. Pacientes y metodos. Basados en la escala de valoracion funcional para la esclerosis lateral amiotrofica revisada, se establecieron cuatro dominios (bulbar, destrezas manuales, funcion motora gruesa y funcion respiratoria). A cada item se le asigno una puntuacion de 0 si su calificacion era igual o mayor de 3 (independencia), o 1 si su calificacion era menor de 3 (dependencia). La escala de clasificacion funcional se definio desde el estadio 1 (sin perdida de independencia en ningun dominio) hasta el estadio 5 (perdida de independencia en los cuatro dominios). Esta clasificacion se correlaciono con la necesidad de ayudas externas, la calidad de vida aplicando la escala del cuestionario de evaluacion de la esclerosis lateral amiotrofica-40, la fuerza muscular y la sobrevida. Resultados. De un total de 244 pacientes, el 14,3% se encontraba en estadio 1; el 23,8%, en estadio 2; el 21,3%, en estadio 3; el 19,3%, en estadio 4; y el 21,3%, en estadio 5. Fuerza muscular y calidad de vida fueron inversamente proporcionales a la etapa de la enfermedad. La necesidad de ayudas externas se relaciona directamente con el aumento de los estadios de la enfermedad de 1 a 5 (p < 0,012). Se encontro una mayor sobrevida de los pacientes en los estadios 1 y 2 con respecto a los estadios 3, 4 y 5 (p = 0,004). Conclusion. El sistema de clasificacion propuesto es de facil aplicacion y se correlaciona bien con la clinica del paciente, su calidad de vida, el requerimiento de recursos y la sobrevida.

El colecho favorece la práctica de la lactancia materna y no aumenta el riesgo de muerte súbita del lactante. Dormir con los padres / Bed-sharing favours the practice of breastfeeding and does not increase the risk of sudden infant death syndrome. Sleeping with parents

La práctica de los padres de dormir junto a sus hijos ha sido una constante en la humanidad. Con el aumento en la prevalencia y duración de la lactancia materna, se ha observado paralelamente un aumento de esa práctica, que posiblemente se dé con más frecuencia que la reconocida en las encuestas. Los estudios han demostrado interrelación y mutua potenciación entre lactancia materna y colecho. Las asociaciones y organizaciones pediátricas recomiendan evitar el colecho, por relacionarlo con la muerte súbita del lactante. Se basan, sin embargo, en estudios en su mayoría no controlados, bajo la influencia de factores de riesgo no tenidos en cuenta. Los autores, tras una revisión exhaustiva sobre colecho, lactancia y muerte súbita del lactante, encuentran el colecho como una práctica beneficiosa para la lactancia y concluyen que, bien practicado, evitando factores de riesgo, no guarda relación con la muerte súbita del lactante (AU)

The practice of bed-sharing by parents and their offspring has been a common behaviour among humans. In parallel with the increase of breastfeeding rates, a higher frequency of bed-sharing has been observed worldwide. And, it is probable that it occurs more frequently than what appears reflected in surveys. There seems to be an interrelated and mutually enhanced effect between breastfeeding and bed-sharing. Pediatric associations and health organizations have warned against the practice of bed-sharing based on studies that describe a link between this practice and Sudden Infant Death Syndrome (SIDS). However, many were non-controlled studies that did not include other potentially risky circumstances. After a thoroughly review of the available literature, the authors have found the practice of bed-sharing to be of benefit on the basis of a warm and close-up infant care approach and calls for recognition and avoidance of risky situations that could represent a threat for infant life (AU)

Uso del chupete y lactancia materna / Use of pacifiers and breastfeeding

El uso del chupete se encuentra muy arraigado en las sociedades desarrolladas, ya que calma el llanto del bebé, ayuda a conciliar el sueño, y reduce el estrés y el dolor en procedimientos desagradables. Su uso se ha relacionado con una menor duración y exclusividad de la lactancia materna, aumento de otitis media, problemas dentales y riesgo de accidentes. Además, estudios recientes relacionan su uso, particularmente durante el sueño, con disminución del riesgo de muerte súbita del lactante. Otros beneficios demostrados son su efecto analgésico y el estímulo de la succión no nutritiva en niños pretérmino y a término. El debate sobre su utilización o no es actualmente motivo de controversia, pero es importante que los profesionales de la salud y los padres conozcan los riesgos y beneficios que conlleva el uso del chupete. Dada la controversia actual, el Comité de Lactancia Materna de la Asociación Española de Pediatría ha realizado, a la luz de las pruebas disponibles actualmente, una revisión del tema en relación con la lactancia materna (AU)

Pacifiers are widely used in developed societies. They are used for soothing infants, reducing their stress and pain during procedures and to help them sleep. The use of pacifiers has been associated, however, with a shorter duration and exclusivity of breastfeeding, with higher rates of otitis media and dental problems, as well as a higher risk of accidents during infancy. Recent studies have also described a relationship between pacifier use and SIDS, especially when used during infant is sleep. Other described benefits are analgesia and stimulation of non-nutritive sucking in preterm and term infants. There is, at present, wide debate and controversy on whether or not to recommend its use; thus it seems important for professionals and parents to be aware of the risks and benefits associated to its use, particularly related to breast feeding. Due to the existing controversy of scientific findings, the Committee on Breastfeeding of the Spanish Paediatrics Society, publishes this review, trying to summarise present evidence with the objective of, after analysing scientific results and recommendations, making recommendations regarding the use of the pacifier in the breastfed infant (AU)

[Use of pacifiers and breastfeeding]. / Uso del chupete y lactancia materna.

Pacifiers are widely used in developed societies. They are used for soothing infants, reducing their stress and pain during procedures and to help them sleep. The use of pacifiers has been associated, however, with a shorter duration and exclusivity of breastfeeding, with higher rates of otitis media and dental problems, as well as a higher risk of accidents during infancy. Recent studies have also described a relationship between pacifier use and SIDS, especially when used during infant́s sleep. Other described benefits are analgesia and stimulation of non-nutritive sucking in preterm and term infants. There is, at present, wide debate and controversy on whether or not to recommend its use; thus it seems important for professionals and parents to be aware of the risks and benefits associated to its use, particularly related to breastfeeding. Due to the existing controversy of scientific findings, the Committee on Breastfeeding of the Spanish Paediatrics Society, publishes this review, trying to summarise present evidence with the objective of, after analysing scientific results and recommendations, making recommendations regarding the use of the pacifier in the breastfed infant.

Deleterious effects induced by oxidative stress in liver nuclei from rats receiving an alcohol-containing liquid diet.

Highly purified rat-liver nuclei were previously shown to have nuclear ethanol (EtOH) metabolizing system able to bioactivate alcohol to acetaldehyde and 1-hydroxyethyl radicals. These reactive metabolites were able to covalently bind to nuclear proteins and lipids potentially being able to provoke oxidative stress of nuclear components. In this study, the above-mentioned possibility was explored. Sprague Dawley male rats (125-150 g) were fed a standard Lieber and De Carli liquid diet for 28 days. Controls were pair-fed with a diet, in which EtOH was isocalorically replaced with carbohydrate. The presence of a chlorzoxazone hydroxylase activity inducible by the repetitive EtOH drinking further suggested the presence of CYP2E1 in the highly purified nuclei. Nuclei from EtOH-drinking rats evidenced significantly increased susceptibility to a t-butyl hydroperoxide challenge as detected by chemiluminescence emission, increased formation of protein carbonyls, and decreased content of protein sulfhydryls. In contrast, no significant changes in the nuclear lipid hydroperoxides formation or even decreases in the 8-oxo-7,8-dihydro-2-deoxyguanosine were observed. No significant differences were observed in different parameters of the alkaline Comet assay. In immunohistochemical studies performed, no expression of p53 was observed in the livers of the animals under the experimental conditions tested. Since nuclear proteins and lipids are known to play a role in cell growth, differentiation, repair and signaling, their alterations by either oxidative stress, or by covalent binding might be of relevance to liver tumor promotion.

Acetaldehyde accumulation in rat mammary tissue after an acute treatment with alcohol.

Previous studies reported the presence in rat mammary tissue of a cytosolic xanthine oxidoreductase pathway for the metabolism of alcohol to acetaldehyde and hydroxyl radicals and to the microsomal biotransformation of ethanol to acetaldehyde. It was also reported that after chronic ethanol drinking stressful oxidative conditions can be observed. The present work reports that even after single doses of ethanol, given at three different levels (6.3 g kg(-1); 3.8 g kg(-1) or 0.6 g kg(-1) p.o.), acetaldehyde accumulates for prolonged periods of time in the mammary tissue to reach concentrations higher than in blood (e.g. 5.1+/-1.2 nmol g(-1) versus 0.2+/-0.1 nmol ml(-1), for 6.3 g kg(-1) dose, 6 h after intoxication). The presence in rat mammary tissue of low activities of additional enzymes able to generate acetaldehyde was established (alcohol dehydrogenase: 0.97+/-0.84 mU mg(-1) protein; CYP2E1: 1.30+/-0.12 x 10(-2) pmol 4-nitrocatechol min(-1) mg(-1) protein) and a low activity of aldehyde dehydrogenase was observed in the cytosolic, mitochondrial and microsomal fractions (0.02+/-0.04; 0.35+/-0.09 and 0.72+/-0.19 mU mg(-1) protein, respectively). After a single high dose of ethanol, an increased susceptibility to oxidative stress was observed, as evidenced by changes in the shape of t-butylhydroperoxide induced emission of chemiluminescence in mammary tissue (6.3 g kg(-1) dose; at 3 and 6 h). In summary, the results show that even after single doses of ethanol, acetaldehyde, either formed in situ or arriving via blood, tends to accumulate in mammary tissue and that this condition might decrease cell defenses against injury.

Fuzzy clustering-based segmented attenuation correction in whole-body PET imaging.

Segmented attenuation correction is now a widely accepted technique to reduce noise propagation from transmission scanning in positron emission tomography (PET). In this paper, we present a new method for segmenting transmission images in whole-body scanning. This reduces the noise in the correction maps while still correcting for differing attenuation coefficients of specific tissues. Based on the fuzzy C-means (FCM) algorithm, the method segments the PET transmission images into a given number of clusters to extract specific areas of differing attenuation such as air, the lungs and soft tissue, preceded by a median filtering procedure. The reconstructed transmission image voxels are, therefore, segmented into populations of uniform attenuation based on knowledge of the human anatomy. The clustering procedure starts with an overspecified number of clusters followed by a merging process to group clusters with similar properties (redundant clusters) and removal of some undesired substructures using anatomical knowledge. The method is unsupervised, adaptive and allows the classification of both pre- or post-injection transmission images obtained using either coincident 68Ge or single-photon 137Cs sources into main tissue components in terms of attenuation coefficients. A high-quality transmission image of the scanner bed is obtained from a high statistics scan and added to the transmission image. The segmented transmission images are then forward projected to generate attenuation correction factors to be used for the reconstruction of the corresponding emission scan. The technique has been tested on a chest phantom simulating the lungs, heart cavity and the spine, the Rando-Alderson phantom, and whole-body clinical PET studies showing a remarkable improvement in image quality, a clear reduction of noise propagation from transmission into emission data allowing for reduction of transmission scan duration. There was very good correlation (R2 = 0.96) between maximum standardized uptake values (SUVs) in lung nodules measured on images reconstructed with measured and segmented attenuation correction with a statistically significant decrease in SUV (17.03% +/- 8.4%, P < 0.01) on the latter images, whereas no proof of statistically significant differences on the average SUVs was observed. Finally, the potential of the FCM algorithm as a segmentation method and its limitations as well as other prospective applications of the technique are discussed.

Cytochrome P450 reductase-mediated anaerobic biotransformation of ethanol to 1-hydroxyethyl-free radicals and acetaldehyde.

The ability of cytochrome P450 reductase to metabolize ethanol (EtOH) to acetaldehyde (AC) and 1-hydroxyethyl free radicals (1HEt) in anaerobic media was studied. Determination of AC was made by GC-FID analysis of the head space of incubation mixtures. The formation of 1HEt was established by GC-MS analysis of the adduct formed between the radical and the spin trap PBN. Results showed that pure human P450 reductase is able to biotransform EtOH to AC and 1HEt in a NADPH-dependent process under an oxygen-free nitrogen atmosphere. Pure FAD in the presence of NADPH was also able to generate AC and 1HEt from the alcohol. Anaerobic incubation mixtures containing either rat liver microsomes or pure nuclei were also able to biotransform EtOH to AC and 1HEt in the presence of NADPH. These processes were inhibited by antibody against rat liver microsomal P450 reductase. Results suggest that semiquinone forms of the flavin in P450 reductase may biotransform EtOH. These reactions might be of some significance in tissues where the P450 reductase is present in the absence of specific forms of cytochrome P450 known to be involved in EtOH metabolism (e.g. CYP2E1). However the toxicological significance of this enzymatic process remains to be established.

Estimation of torque on mechanical heart valves due to magnetic resonance imaging including an estimation of the significance of the Lenz effect using a computational model.

Mitral and aortic valve replacement is a procedure which is common in cardiac surgery. Some of these replacement valves are mechanical and contain moving metal parts. Should the patient in whom such a valve has been implanted be involved in magnetic resonance imaging, there is a possible dangerous interaction between the moving metal parts and the static magnetic field due to the Lenz effect. Mathematical models of two relatively common forms of single-leaflet valves have been derived and the magnitude of the torque which opposes the motion of the valve leaflet has been calculated for a valve disc of solid metal. In addition, a differential model of a ring-strengthener valve type has been considered to determine the likely significance of the Lenz effect in the context of the human heart. For common magnetic field strengths at present, i.e. 1 to 2 T, the effect is not particularly significant. However, there is a marked increase in back pressure as static magnetic field strength increases. There are concerns that, since field strengths in the range 3 to 4 T are increasingly being used, the Lenz effect could become significant. At 5 to 10 T the malfunction of the mechanical heart valve could cause the heart to behave as though it is diseased. For unhealthy or old patients this could possibly prove fatal.

Lactancia materna y trabajo / Breast feeding and working

No disponible

A liver nuclear ethanol metabolizing system. Formation of metabolites that bind covalently to macromolecules and lipids.

Recent studies from the laboratory reported the presence in highly purified liver nuclear preparations free of endoplasmic reticulum, mitochondria or cytosol, of an ethanol metabolizing group of enzymes (NEMS) leading to acetaldehyde and to hydroxyl and 1-hydroxyethyl (1HEt) free radicals. In the present study it is reported that when NEMS metabolize [14C]ethanol using NADPH as cofactor, its reactive metabolites bind covalently to nuclear proteins and lipids. No covalent binding to DNA was detected with presently used procedures. The covalent binding to nuclear proteins was acid labile and is mostly attributable to acetaldehyde. Additional evidence was attempted through studies where the acetaldehyde was identified as its 2,4-dinitrophenylhydrazone or as its pentafluorphenylhydrazone and gas chromatography (GC) analysis using electron capture detection. Values obtained were close to detection limit and of variable nature. The covalent binding to nuclear lipids involved phospholipids, fatty acids and esters and cholesterol free and esterified and it was only partially labile to acid treatment. Production of ethanol reactive metabolites such as acetaldehyde and free radicals, nearby liver nuclear DNA and nuclear proteins or lipids, might have significant toxicological consequences.

DNA bases attack by reactive metabolites produced during carbon tetrachloride biotransformation and promotion of liver microsomal lipid peroxidation.

Free radicals produced during carbon tetrachloride biotransformation and the promoted lipid peroxidation process of liver microsomal lipids are able to attack the DNA bases guanine, cytosine and thymine to give at least three altered bases. They were identified as 2,6-diamino-4-hydroxy-5-formamidopyrimidine (FapyGua); 5-hydroxycytosine (5OHCyt) and 5-hydroxymethyluracil (5OHMeU). No adenine adducts were detected. If these altered bases were formed during carbon tetrachloride poisoning and were not adequately repaired before cell replication, serious permanent consequences for liver cell DNA could be expected and this might be somehow involved in the liver carcinogenic effects of the haloalkane.

[Breast feeding and length of hospitalization]. / Lactancia y estancia hospitalaria.

One of the important tasks for a nurse is to insure that the newborn receives all the nourishment that it needs. A well fed baby is healthier, experiences a shorter hospital stay and develops a stronger bond with its mother. To prove this point a study was performed on a group of low birth weight newborns (free of other pathological symptoms) to compare nutrition against hospitalization time. 85 children of both sexes were divided into 3 groups: premature but of normal gestational size, premature but small for gestational size, and full term but small for gestational size; all had a birth weight superior to 2 kilos and were examined postpartum on their first and third week. The groups were then subdivided into 2 groups: one received only artificial milk formula and the other group received their mothers' milk through a bottle. The children that drank the maternal milk required fewer days in the hospital (18 +/- 6 days versus 27 +/- 7 days for those drinking only formula) and had a smaller percentage of weight loss after birth (3.7 +/- 2.0% versus 5.2 +/- 2.9%), demonstrating a significant difference in their overall health.

5-Methylcytosine attack by hydroxyl free radicals and during carbon tetrachloride promoted liver microsomal lipid peroxidation: structure of reaction products.

We recently reported that trichloromethyl and trichloromethylperoxyl radicals attack 5-methylcytosine (5MC) to give several products derived from hydroxylation, deamination or halogenation reactions. Hydroxyl radicals and lipid peroxidation (LP) are more frequently involved in deleterious pathological or toxicological processes than those CCl4 derived radicals and thus we considered it of interest to test whether they also alter 5MC. We observed that OH radicals generated by 0.1 mM Fe2+/2.5 mM H202 at 25 degrees C for 1 h led to the production of 5-hydroxymethylcytosine (5MHC). When OH generation was performed with UV light (254 nm, 3400 muWatt/cm2) and 2mM H202 during 4 min at 25 degrees C the following products were observed: 5-hydroxy-5-methylhydantoin, 5-hydroxyhydantoin, 5MHC, thymine glycol (two isomers) and 5-hydroxymethyl-6-hydroxycytosine. When 5MC was exposed to liver microsomal suspensions in the presence of NADPH generating system and carbon tetrachloride during 1 h at 37 degrees C and under air, the formation of only 5HMC was observed. Detection and identification of all reaction products was done by GC/MS analysis of trimethylsilyl derivatives of the bases. If similar reactions occurred in DNA, these results might be of relevance to gene control, differentiation and carcinogenesis.

Dithiothreitol inhibitory effects on carbon tetrachloride-promoted NADPH-dependent lipid peroxidation in liver microsomal suspensions.

In previous studies from our laboratory evidence was provided that generation in vivo of dithiothreitol (DTT) from DTT tetraacetate (DTTAC) was accompanied with preventive effects against CCl4-induced necrogenic effects on the liver. In that study, we reported the ability of treatment to decrease the intensity of covalent binding (CB) of the CCl4 reactive metabolites to cellular components but no evidence of preventive effects on CCl4-induced lipid peroxidation (LP) was obtained by the diene hyperconjugation technique. Now, we report that DTT at concentrations 1 or 3 mM inhibit at steps of the process after diene conjugation and prior to malondialdehyde formation. One of those steps might involve peroxides since we observed that DTT is able to significantly react with benzoyl peroxide in a model system. Others might also involve free radicals for in the present study we observed the reaction of DTT with trichloromethyl or trichloromethylperoxy free radicals generated from CBrCl3 in a model system. Reactions of DTT with free radicals and peroxides resulting in inhibition of CB and LP might be critical components in the preventive effects of DTTAC against CCl4-induced liver damage.

Decreased incorporation of 14C-leucine in different liver nuclear protein fractions at early stages of carbon tetrachloride poisoning in the rat.

Administration of CCl4 to 12-14 h starved Sprague Dawley male rats (220-240 g) at a dose of 5 ml of a 20% (v/v) olive oil solution/kg i.p. decreased the incorporation of 14C-leucine into microsomal and nuclear proteins at 1 or 2 h after the hepatotoxin. Decreased amino acid incorporation capacity in nuclear but not in microsomal proteins returned to control values at 4 h after poisoning. Cycloheximide given i.p. at a dose of 1 mg/kg in saline either alone or before CCl4 also decreased to a similar or greater extent the incorporation of 14C-leucine into both, microsomal and nuclear proteins at 1 h. The CCl4-induced decrease in amino acid incorporation was observable and significant even 1 h after CCl4 and involved histone and different non-histone nuclear protein fractions. Results suggest that decreased protein synthesis at the endoplasmic reticulum occurring in the very early stages of CCl4 poisoning might provoke temporary deficiencies in protein supplies to nuclei with as yet unknown consequences. However, some of the proteins involved have major regulatory properties in DNA expression.

Non-genotoxic carcinogens. Approaches to their risk assessment.

Epidemiological studies support the idea that most human cancers are related to chemicals present in the human environment. In turn, chemicals are believed to cause cancer via either genotoxic or non-genotoxic mechanisms. There were described in literature several simple, rapid and inexpensive short term tests to reasonably predict the genotoxic nature of chemicals but in contrast, there is no reliable test or battery of tests available to predict the carcinogenicity of non-genotoxic compounds and this poses a major problem to their risk assessment. In addition, there are conflictive opinions about risk assessment needs for both classes of carcinogens. Some workers believe that for non-genotoxic carcinogens, thresholds for exposure can be drawn while others do not. In this review, the reasons behind both of these opinions and the present hypotheses about the mechanism of action of non-genotoxic carcinogens are described and analyzed in relation to future needs.

[Naproxen sodium in the treatment of otitis]. / Naproxeno sódico en el tratamiento de las otitis.

OBJECTIVE: To assess the analgesic and anti-inflammatory value of sodium Naproxen in the treatment of otitis. DESIGN: A prospective study. There were interventions, but no controls. There was not a random distribution of the sample. SITE. Outpatient clinics in a Santander hospital. PATIENTS AND OTHER PARTICIPANTS: Patients presenting symptoms of acute or chronic otitis. INTERVENTIONS: A group of 20 patients with acute otitis and a second group of 15 with chronic otitis were treated normally; while 20 other patients suffering acute otitis and 17 with chronic otitis received in addition to normal treatment 550 mg of sodium naproxen every 12 hours. MAIN MEASUREMENTS AND RESULTS: The evolution of the clinical description was evaluated along the following parameters: perforation of the tympanum, otorrhea, pain, vertigo, migraines, hypoacusis and audiometries in acute cases of otitis; and all these and also tympanic biopsy in chronic cases. The results obtained indicated a statistically significant anatomical-pathological improvement in chronic cases of otitis treated with sodium naproxen; whereas in cases of acute otitis, these differences were observed in parameters such as hypoacusis, tympanometry, perforation of the tympanum and effectiveness of and tolerance towards additional treatment with sodium Naproxen. CONCLUSIONS: On the basis of the study's results as well as the high level of tolerance and absence of undesirable effects, we made a positive evaluation of the introduction of the aforesaid anti-inflammatory into the normal treatment of cases of otitis.