Relevancia de la PET/TC con [18F]FDG en la detección de enfermedad localizada en el colon en pacientes estudiados por bacteriemia o endocarditis infecciosa causadas por microorganismos enteropatógenos / Relevance of [18F]FDG-PET/CT in the detection of colon pathology in patients studied by bacteriemia or infectious endocarditis caused by enteropathogenic microorganisms

Objetivo La asociación entre la endocarditis infecciosa (EI) por Streptococcus gallolyticus y las lesiones malignas del tracto gastrointestinal está bien descrita. Asumimos que otros microorganismos enteropatógenos, como el Streptococcus viridans y Enterococcus faecalis también pueden estar relacionados con la enfermedad colorrectal. Nuestro objetivo fue determinar la frecuencia de depósitos focales de la [18F]FDG en localización colorrectal, sugestivos de lesiones tumorales, y su correlación con la enfermedad de colon y recto en pacientes con infección causada por diferentes microorganismos comensales del tracto gastrointestinal. Métodos Examinamos retrospectivamente 61 pacientes con diagnóstico de bacteriemia y de EI (posible o concluyente) según los criterios de Duke y causada por microorganismos enteropatógenos, y que fueron sometidos a una PET/TC de cuerpo entero con [18F]FDG en nuestra institución. Buscamos depósitos de la [18F]FDG en localización colorrectal, así como la presencia de lesiones morfológicas. A todos los pacientes con EI se les realizó una colonoscopia completa y los resultados histológicos se clasificaron según 4 grupos: lesión maligna, lesión premaligna, lesión benigna y ausencia de lesión. Se evaluó la correlación existente entre los hallazgos de la PET/TC con [18F]FDG y el diagnóstico histopatológico y el microorganismo implicado. Resultados La PET/TC detectó 20 depósitos de [18F]FDG en localización colorrectal (32,79%-OR: 47,28), 2 de ellos en pacientes con bacteriemia (16,7%) confirmados como lesiones malignas y premalignas y 18 en el grupo con EI (36,6%), 17 de ellos correspondientes a enfermedad colorrectal: 11 lesiones malignas, 5 premalignas y una benigna. En el subgrupo con EI la colonoscopia detectó lesiones colorrectales en el 51,02% de los pacientes: 11 malignas, 8 premalignas y 6 benignas. En el subgrupo de Streptococcus spp. se detectó una mayor incidencia de depósitos de [18F]FDG en localización colorrectal (AU)

Objective Association between Streptococcus gallolyticus infective endocarditis (IE) and malignant lesions of the gastrointestinal tract is well described. We hypothesize that other enteropathogenic microorganisms, such as Streptococcus viridans and Enterococcus faecalis are also related with colorectal pathology. Our aim is to determine the frequency of focal colorectal FDG deposits, suggestive of tumoral lesions and their correlation with colorectal pathology, in patients with infection caused by different commensal microorganisms of the gastrointestinal tract. Methods We retrospectively examined 61 patients diagnosed with bacteremia (BSI) and IE (possible or definite) according to Duke's criteria, caused by enteropathogenic microorganisms, who underwent a full-body [18F]FDG-PET/CT in our institution. We looked for colorrectal FDG deposits and morphological lesions. All IE patients underwent a complete colonoscopy and the histological results were classified into four groups: malignant lesion, premalignant lesion, benign lesion and no lesion. We evaluated the correlation between the findings of the [18F]FDG-PET/CT with the histopathological diagnosis and the involved microorganism. Results PET/CT detected 20 colorectal FDG deposits (32.79%-OR: 47.28), 2 within bacteriemic patients (16.7%) confirmed as malignant and premalignant lesions and 18 in IE group (36.6%), 17 of them corresponding to colorrectal pathology: 11 malignant, 5 premalignant and 1 benign lesions. In the IE subgroup, the colonoscopy detected colorectal lesions in 51.02% of the patients: 11 malignant, 8 premalignant and 6 benign. We found a higher incidence of colorectal FDG deposits in Streptococcus spp. subgroup. Regarding the anatomopathological colonic findings there was a predominance of patients affected by S. viridans, followed by E. faecalis and S. gallolyticus (AU)

Magnetic properties of the double perovskites Sm2Mn1+x Co1-x O6 (x = 0, 0.05, 0.12 and 0.26).

The magnetic properties of the double perovskites Sm2Mn1+x Co1-x O6 (x = 0, 0.05, 0.12 and 0.26) were investigated. It was found that the Curie temperature, the lattice parameters and the net magnetic moments increased for increasing amounts of Co. An irreversible behavior was observed by measuring the magnetization after cooling the sample with and without applied magnetic fields (H). The temperature below which the irreversibility was observed is H dependent and the data were nicely fit to de Almeida-Thouless lines. The ac magnetic susceptibility was measured for frequencies f  in the range 0.03-10 kHz yielding [Formula: see text] for the shifting in the freezing temperature per decade of f . The spin-dynamics were found to follow a power-law with a product of the critical exponents [Formula: see text] of about 4.99. The overall results are understood within a framework where the variation in the bonding angle associated to the super-exchange interactions are taken into consideration.

Effects of feeding flaxseed on performance, carcass trait, and meat fatty acid composition of Guinea pigs (Cavia procellus) under northern Peruvian condition.

A study was conducted to determine the effects of flaxseed supplementation on performance, carcass traits, and hindleg fatty acid composition of guinea pigs. Sixty male and female weaned guinea pigs (1 month old, five animals/cage) were blocked by sex and bodyweight and randomly fed 0 (control) or 100 g/kg flaxseed concentrate diets (15 g/animal) plus ad libitum fresh alfalfa for 30 days. Results showed that flaxseed supplementation had no influence on animal performance. However, final body weight (P = 0.035), total feed intake (P = 0.019), and body weight gain (P < 0.001) were higher in male than female guinea pigs. Similar results were also observed for carcass composition (i.e., hot, chilled, and reference carcass weights). Inclusion of flaxseed reduced saturated (P < 0.001), mono-unsaturated (P = 0.004), and increased (P < 0.001) polyunsaturated (PUFA) fatty acid concentrations in hindlegs. Concentrations of linolenic acid and n-3 PUFA increased (P < 0.001) by 49.7 and 37.1%, respectively as a result of flaxseed inclusion. It was concluded that feeding flaxseed to guinea pigs at 100 g/kg of the concentrate diets improves meat PUFA concentrations with no adverse effects on performance or carcass composition.

Structural and magnetic properties of core-shell Au/Fe3O4 nanoparticles.

We present a systematic study of core-shell Au/Fe3O4 nanoparticles produced by thermal decomposition under mild conditions. The morphology and crystal structure of the nanoparticles revealed the presence of Au core of d = (6.9 ± 1.0) nm surrounded by Fe3O4 shell with a thickness of ~3.5 nm, epitaxially grown onto the Au core surface. The Au/Fe3O4 core-shell structure was demonstrated by high angle annular dark field scanning transmission electron microscopy analysis. The magnetite shell grown on top of the Au nanoparticle displayed a thermal blocking state at temperatures below TB = 59 K and a relaxed state well above TB. Remarkably, an exchange bias effect was observed when cooling down the samples below room temperature under an external magnetic field. Moreover, the exchange bias field (HEX) started to appear at T~40 K and its value increased by decreasing the temperature. This effect has been assigned to the interaction of spins located in the magnetically disordered regions (in the inner and outer surface of the Fe3O4 shell) and spins located in the ordered region of the Fe3O4 shell.

Thermodynamic temperature assignment to the point of inflection of the melting curve of high-temperature fixed points.

The thermodynamic temperature of the point of inflection of the melting transition of Re-C, Pt-C and Co-C eutectics has been determined to be 2747.84 ± 0.35 K, 2011.43 ± 0.18 K and 1597.39 ± 0.13 K, respectively, and the thermodynamic temperature of the freezing transition of Cu has been determined to be 1357.80 ± 0.08 K, where the ± symbol represents 95% coverage. These results are the best consensus estimates obtained from measurements made using various spectroradiometric primary thermometry techniques by nine different national metrology institutes. The good agreement between the institutes suggests that spectroradiometric thermometry techniques are sufficiently mature (at least in those institutes) to allow the direct realization of thermodynamic temperature above 1234 K (rather than the use of a temperature scale) and that metal-carbon eutectics can be used as high-temperature fixed points for thermodynamic temperature dissemination. The results directly support the developing mise en pratique for the definition of the kelvin to include direct measurement of thermodynamic temperature.

Statistical comparison of dissolution profiles to predict the bioequivalence of extended release formulations.

Appropriate setting of dissolution specification of extended release (ER) formulations should include precise definition of a multidimensional space of complex definition and interpretation, including limits in dissolution parameters, lag time (t-lag), variability, and goodness of fit. This study aimed to set dissolution specifications of ER by developing drug-specific dissolution profile comparison tests (DPC tests) that are able to detect differences in release profiles between ER formulations that represent a lack of bioequivalence (BE). Dissolution profiles of test formulations were simulated using the Weibull and Hill models. Differential equations based in vivo-in vitro correlation (IVIVC) models were used to simulate plasma concentrations. BE trial simulations were employed to find the formulations likely to be declared bioequivalent and nonbioequivalent (BE space). Customization of DPC tests was made by adjusting the delta of a recently described tolerated difference test (TDT) or the limits of rejection of f2. Drug ka (especially if ka is small), formulation lag time (t-lag), the number of subjects included in the BE studies, and the number of sampled time points in the DPC test were the factors that affected the most these setups of dissolution specifications. Another recently described DPC test, permutation test (PT), showed excellent statistical power. All the formulations declared as similar with PT were also bioequivalent. Similar case-specific studies may support the biowaiving of ER drug formulations based on customized DPC tests.

Prueba de sensibilidad antimicrobiana de cepasde Salmonella grupo D (móviles e inmóviles) aisladasde ponedoras comerciales en Colombia / Antimicrobial susceptibility test of isolates of Salmonella group D (mobile and non mobile) from commercial laying hens in Colombia

Las infecciones originadas por bacterias del género Salmonella son una de las principalescausas de pérdidas económicas en la industria avícola, se caracterizan generalmentepor la presentación de cuadros diarreicos y septicémicos que llevan a las aves a unamarcada disminución en la producción y a la muerte. En Colombia, debido al efectonegativo que produce Salmonella spp. en las aves, y con el objetivo de poder controlarla enfermedad, se utiliza una gran variedad de productos antimicrobianos, de los cuales no se posee suficiente información acerca de su comportamiento en cuanto asensibilidad y resistencia frente a las cepas de Salmonella spp. de campo. El objetivo de este estudio fue determinar la respuesta de 20 cepas de Salmonellas grupo D (móviles einmóviles) aisladas de aves ponedoras comerciales en Colombia frente a diferentes antimicrobianos. Para su aislamiento y tipificación se utilizaron técnicas microbiológicas convencionales, pruebas bioquímicas, serológicas y pruebas de susceptibilidad a los antibióticos por difusión en agar. Los resultados revelaron una resistencia total hacia la estreptomicina, seguida de altas resistencias para tetraciclina y florfenicol, y una menor resistencia a productos como fosfomicina y cloramfenicol.

Infections caused by Salmonella bacteria are a major cause of economic losses in thepoultry industry, because caused mainly by the presentation of diarrheas and septicemic birds leading to a marked decrease in the production death. In Colombia due to the negative effect by Salmonella spp. in poultry, and with the aim of controlling the disease, the people have been using a variety of antimicrobials, which do not possess sufficient information about its behavior in terms of sensitivity and resistance againststrains of Salmonella spp. field. The aim of this study was to determine the response of20 strains of Salmonella group D (mobile and non mobile) isolated from commercial laying hens in Colombia against different antimicrobials. For the isolation and characterization are using conventional microbiological techniques, biochemical tests, serological testing and antibiotic susceptibility by agar diffusion. The results revealed a total resistance to streptomycin, followed by tetracycline and Florfenicol and less resistance to products such as Fosfomycin and chloramphenicol.

[Anesthetic management during removal of a giant intrathoracic mass]. / Manejo anestésico en la exéresis de un tumor intratorácico gigante.

We report the case of a young woman with a giant intrathoracic angiomyolipoma accounting for 10% of her weight and occupying 75% of the right hemithorax and 30% of the left. Before anesthetic induction, an arterial line and a central venous catheter were applied for monitoring; neck and thoracic punctures were avoided. The trachea was intubated with a double lumen tube after provision of sedation and analgesia with remifentanil-midazolam and topical anesthesia of the larynx. A rigid bronchoscope and extracorporeal circulation were available at all times and muscle relaxants were avoided. Ventilation was maintained with pressure support until the mass effect was resolved. The patient was transferred to the intensive care unit, extubated after 24 hours, and discharged 5 days after surgery. We describe the recommendations for perioperative management in cases involving this type of tumor and the complications that can develop. Recent symptoms, diagnostic images, and the results of lung function tests provide information for guiding the anesthetic approach. The obstructive ventilatory compromise caused by a giant mass depends more on location than size. Extracorporeal circulation or rigid bronchoscopy might be needed at any time during surgery.

Magnesium for acute traumatic brain injury.

BACKGROUND: Acute traumatic brain injury is a leading cause of death and disability in young adults. Magnesium had been considered as a potential therapeutic tool because of its activity on NMDA-receptors, calcium channels and neuron membranes. Animals studies have indicated a beneficial effect of magnesium on outcome after brain injury, but its efficacy in humans is unknown. OBJECTIVES: To quantify the effect of magnesium administration on mortality and morbidity in patients with acute traumatic brain injury. SEARCH STRATEGY: We searched the Cochrane Injuries Group's specialised register, Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, National Research Register, Current Controlled Trials, SIGLE, LILACS, Zetoc. The searches were conducted in July 2005. SELECTION CRITERIA: We included all randomized controlled trials comparing any magnesium salt with no magnesium or with placebo, in patients following acute traumatic brain injury. DATA COLLECTION AND ANALYSIS: Two authors independently screened search results and assessed the full texts of potentially relevant studies for inclusion. Data were extracted and methodological quality was examined. MAIN RESULTS: Three studies met the inclusion criteria, one of which is an ongoing study. Two studies were included in the analysis. No data on mortality were available. For Glasgow Outcome Score at six months the pooled WMD = 0.55 (95% CI -0.15 to 1.26), P = 0.12. AUTHORS' CONCLUSIONS: There is currently no evidence to support the use of magnesium salts in patients with acute traumatic brain injury.

Manejo anestésico en la exéresis de un tumor intratorácico gigante / Anesthetic management during removal of a giant intrathoracic mass

Se describe el caso de una mujer joven con un angiomiolipomagigante intratorácico correspondiente al 10%de su peso, que ocupaba 75% del hemitórax derecho y30% del izquierdo. Previo a la inducción anestésica semonitorizó a la paciente de forma invasiva, evitando losaccesos centrales en cuello o tórax. La intubación se realizócon tubo de doble luz izquierdo, previa sedaciónanalgesiacon remifentanilo-midazolam y anestesia tópicasobre las estructuras laríngeas. Se mantuvodisponibilidad permanente de broncoscopio rígido y circulaciónextracorpórea y se evitó el uso de relajantesmusculares manteniendo la ventilación con soporte depresión hasta que el efecto de masa fue resuelto. Lapaciente fue trasladada a UCI, extubada a las 24 horas ydada de alta a los 5 días del postoperatorio. Se describenlas recomendaciones perioperatorias en este tipo detumores y los posibles tipos de complicaciones.Al enfrentarnos a este tipo de pacientes, la sintomatologíareciente y la evaluación mediante imágenes y pruebasfuncionales nos guiarán en el enfoque anestésico. Elcompromiso obstructivo generado por estas masasgigantes depende principalmente de su localización másque de su tamaño. Cualquier momento del intraoperatoriopuede requerir la necesidad de circulación extracorpóreao broncoscopia rígida

We report the case of a young woman with a giantintrathoracic angiomyolipoma accounting for 10% of herweight and occupying 75% of the right hemithorax and30% of the left. Before anesthetic induction, an arterialline and a central venous catheter were applied for monitoring;neck and thoracic punctures were avoided. Thetrachea was intubated with a double lumen tube afterprovision of sedation and analgesia with remifentanilmidazolamand topical anesthesia of the larynx. A rigidbronchoscope and extracorporeal circulation were availableat all times and muscle relaxants were avoided. Ventilationwas maintained with pressure support until themass effect was resolved. The patient was transferred tothe intensive care unit, extubated after 24 hours, and discharged5 days after surgery. We describe the recommendationsfor perioperative management in cases involvingthis type of tumor and the complications that can develop.Recent symptoms, diagnostic images, and the resultsof lung function tests provide information for guiding theanesthetic approach. The obstructive ventilatory compromisecaused by a giant mass depends more on locationthan size. Extracorporeal circulation or rigid bronchoscopymight be needed at any time during surgery

[Clinical management of terrorist bomb explosions]. / Atención a las víctimas por ataque terrorista con explosivos.

At 07:39 on 11 March 2004 terrorist bomb explosions ocurred in 4 trains in Madrid killing 177 people instantly and 14 more later in the hospital. This report describes the organization, clinical management and patterns of injuries in casualties who were taken to our chil-patients were taken to the Gregorio Marañon hospital and 12 to the children's one. The mean age was 16 years (14-21), Two of them were critically ill and needed intensive care (ITP 5). Tympanic perforations occurred in 81% victims with moderate to severe trauma, shrapnel wounds in 36% and eye lesions in 27%. Among critically ill patients blast lung injury, cranial and abdominal trauma were the most important lesions. Training in AITP courses and hospital logistics were essential in clinical management of these casualties.

Epidemiología de la enfermedad de Meniere en Cantabria / Epidemiology of Meniere´s disease in Cantabria

Objetivos: Conocer las principales características epidemiológicas de la enfermedad de Meniere en Cantabria. Métodos: Se recogieron de forma prospectiva todos los enfermos diagnosticados de Enfermedad de Meniere "definitivo" según los criterios de la AAO-HNS entre los años 1992 y 2002 en el Hospital Sierrallana de Torrelavega (Cantabria). Se calculó la incidencia, prevalencia, distribución por sexos, edad de presentación y si afectaba a uno o ambos oídos. Resultados: Un total de 75 pacientes fueron diagnosticados de enfermedad de Meniere "definitivo" durante dicho periodo. La incidencia fue de 3 casos /100.000 habitantes/año, la prevalencia de 75/100.000 (29 en varones y 46 en mujeres). La edad de diagnóstico más frecuente fue entre los 40 y 60 años. Los casos bilaterales constituyeron el 5,3 por ciento. Conclusiones: La enfermedad de Meniere no es infrecuente en Cantabria. Es más habitual en mujeres entre los 40 y 60 años de edad afectando normalmente a un solo oído (AU)

OBJECTIVES: To know the main epidemiologic characteristics of Meniere's disease in Cantabria. METHODS: All the patients diagnosed of «definitive» Meniere's disease between 1992 and 2002 in Sierrallana Hospital of Torrelavega (Cantabria, Spain) were reviewed. Incidence, prevalence, presence of bilateral disease, age at diagnosis and gender were recorded. RESULTS: A total of 75 patients were diagnosed of «definitive» Meniere's disease during this time. The incidence was 3/100,000 people/year, the prevalence 75/100,000, male/female ratio was 0.38. Most frequent age at onset was between 40 and 60 years and bilateral cases were 5.3%. CONCLUSIONS: Meniere's Disease is not uncommon in Cantabria. It is more prevalent among middle aged women. Bilateral cases are rare (AU)

[Epidemiology of Menière's disease in Cantabria]. / Epidemiología de la enfermedad de Menière en Cantabria.

OBJECTIVES: To know the main epidemiologic characteristics of Meniere's disease in Cantabria. METHODS: All the patients diagnosed of "definitive" Meniere's disease between 1992 and 2002 in Sierrallana Hospital of Torrelavega (Cantabria, Spain) were reviewed. Incidence, prevalence, presence of bilateral disease, age at diagnosis and gender were recorded. RESULTS: A total of 75 patients were diagnosed of "definitive" Meniere's" disease" during this time. The incidence was 3/100,000 people/year, the prevalence 75/100,000, male/female ratio was 0.38. Most frequent age at onset was between 40 and 60 years and bilateral cases were 5.3%. CONCLUSIONS: Meniere's Disease is not uncommon in Cantabria. It is more prevalent among middle aged women. Bilateral cases are rare.

Características audiométricas de la hipoacusia familiar transmitida por herencia mitocondrial (A1555G) / Audiometric characteristics of familial hypoacusia transmitted by mitocondrial inheritance (A1555G)

Objetivos: Determinar las características audiométricas de la hipoacusia familiar secundaria a la mutación A1555G del ADN mitocondrial. Pacientes y métodos: Cincuenta y cinco pacientes portadores de la mutación A1555G del ADN mitocondrial, pertenecientes a 6 familias no relacionadas con hipoacusia neurosensorial no sindrómica, estudiados en el Hospital Sierrallana (Torrelavega, Cantabria) fueron incluidos en este estudio. Cinco de las familias portaban la mutación en homoplasmia y una en heteroplasmia. A todos ellos se les realizó una anamnesis, exploración ORL y audiometría tonal. Resultados: La mayor parte de los pacientes desarrollaron hipoacusia bilateral y simétrica, lentamente progresiva, sobre todo para altas frecuencias. En los pacientes no sometidos a tratamiento aminoglucósido la hipoacusia fue generalmente leve o moderada y de aparición tardía. En 17 casos hubo una exposición previa a medicamentos ototóxicos, desarrollando una pérdida severa de audición en casi todos ellos, uno de los cuales presentaba una sordomudez.No se encontraron diferencias audiométricas entre las familias que presentaron la mutación en homoplasmia y en heteroplasmia. Conclusiones: Los portadores de la mutación A1555G del ADN mitocondrial presentan generalmente una hipoacusia neurosensorial bilateral y simétrica, de grado ligero o moderado, con predominio en altas frecuencias, lentamente progresiva y de comienzo a partir de la segunda década, que se ve agravada de manera importante por el efecto ototóxico de los aminoglucósidos (AU)

OBJECTIVE: To examine the audiometric patterns of familial hearing impairment due to the A1555G mutation in the mitochondrial DNA. PATIENTS AND METHODS: We include 55 subjects with the A1555G mutation from 6 unrelated families, affected by nonsyndromic sensorineural hearing loss and residing in Cantabria. The A1555G mutation was found in homoplasmy in all the families, except in one family, in which it was in heteroplasmy. Aside from standard history taking and general otolaryngological examination, pure tone audiometry was carried out in all patients. RESULTS: Hearing loss was developed by most of the patients. The auditory defect was a slowly progressive bilateral symmetrical sensorineural hearing loss, affecting mainly the high frequencies. In patients in which aminoglycoside ototoxicity could be excluded, hearing loss usually ranged from mild to moderate, with a late onset. In 17 cases there were previous history of treatment with a ototoxic drugs, and most of them developed severe hearing loss. One of them was deaf-mute. No audometric differences between families with the homoplasmic and the heteroplasmic A1555G mutation were observed. CONCLUSIONS: Patients with the A1555G mutation generally present bilateral symmetrical sensorineural hearing loss, ranging from mild to moderate, slowly progressive, which is obvious approximately in the second decade of life and affects specially the high frequencies. Hearing loss severity is increased by treatment with aminoglycosides (AU)

Incidencia de las mutaciones A1555G en el ADN mitocondrial y 35delG en el gen GJB2 (conexina 26) en familias con hipoacusia neurosensorial postlocutiva no sindrómica en Cantabria / Incidence of the mutations A1555G in the mitochondrial DNA and 35delG in the GJB2 gene (connexin-26) in families with late-onset non-syndromic sensorineural hearing loss from Cantabria

Introducción: La hipoacusia neurosensorial es un trastorno con una gran trascendencia social, que afecta aproximadamente al 10 per cent de la población general. Se calcula que en más del 50 per cent de los casos tiene una causa genética. Las dos mutaciones más frecuentemente encontradas en la población española responsables de hipoacusia neurosensorial son la mutación A1555G en el gen del RNA ribosómico 12S del genoma mitocondrial y la mutación 35delG en el gen GJB2 (conexina 26, cromosoma 13). Métodos: Mediante estudio genético se ha determinado la frecuencia de las mutaciones A1555G en el ADN mitocondrial y 35delG en el gen de la conexina 26 en 21 pacientes pertenecientes a 21 familias no consanguíneas y no relacionadas entre sí, con hipoacusia neurosensorial bilateral postlocutiva no sindrómica de Cantabria. Resultados: El estudio mostró la presencia de la mutación A1555G en 6 pacientes, de los cuales 5 tenían antecedentes de exposición a aminoglucósidos. En todos ellos la pérdida auditiva afectaba sobre todo a altas frecuencias. No se detectó la mutación 35delG en ningún paciente. Conclusiones: La mutación A1555G del ADN mitocondrial es frecuente en la población de Cantabria. Debe sospecharse esta mutación y evitar la administración de aminoglucósidos en pacientes pertenecientes a familias con transmisión materna de la hipoacusia y con presencia de miembros con sordera inducida por estos fármacos. La mutación 35delG en el gen GJB2 no parece constituir una causa frecuente en casos familiares de hipoacusia neurosensorial no sindrómica de manifestación postlocutiva en nuestro medio (AU)

INTRODUCTION: Sensorineural deafness is a very common disorder in humans, which affects approximately 10% of the population. Genetic causes are suggested to be responsible for more than half of the cases. The A1555G mutation in the mitochondrial 12S rRNA gene and the 35delG mutation in the GJB2 gene are the most common mutations for sensorineural deafness in the Spanish population. METHODS: A genetic study was carried out in order to determine the frequency of the mutations A1555G in the mitochondrial DNA and 35delG in the connexin-26 gene in 21 patients from 21 non-consanguineous unrelated families affected by late-onset bilateral non-syndromic sensorineural hearing loss from Cantabria. RESULTS: The A1555G mutation was found in 6 patients. Five of these 6 patients had been treated with aminoglycosides. In all of them the auditory impairment affected mainly the high frequencies. The 35delG mutation was not found in any of the patients. CONCLUSIONS: The A1555G mutation in the mitochondrial DNA has been found to be the most common amongst the Cantabrian population. The A1555G mutation should be suspected in those members of families affected by sensorineural hearing impairment with a maternal inheritance pattern and ototoxicity from treatment with aminoglycoside antibiotics. The 35delG mutation in the GJB2 gene does not seem to be a major cause of deafness in families with late-onset non-syndromic sensorineural hearing loss in our area (AU)

[Audiometric features of familial hearing impairment transmitted by mitochondrial inheritance (A1555G)]. / Características audiométricas de la hipoacusia familiar transmitida por herencia mitocondrial (A1555G).

OBJECTIVE: To examine the audiometric patterns of familial hearing impairment due to the A1555G mutation in the mitochondrial DNA. PATIENTS AND METHODS: We include 55 subjects with the A1555G mutation from 6 unrelated families, affected by nonsyndromic sensorineural hearing loss and residing in Cantabria. The A1555G mutation was found in homoplasmy in all the families, except in one family, in which it was in heteroplasmy. Aside from standard history taking and general otolaryngological examination, pure tone audiometry was carried out in all patients. RESULTS: Hearing loss was developed by most of the patients. The auditory defect was a slowly progressive bilateral symmetrical sensorineural hearing loss, affecting mainly the high frequencies. In patients in which aminoglycoside ototoxicity could be excluded, hearing loss usually ranged from mild to moderate, with a late onset. In 17 cases there were previous history of treatment with a ototoxic drugs, and most of them developed severe hearing loss. One of them was deaf-mute. No audometric differences between families with the homoplasmic and the heteroplasmic A1555G mutation were observed. CONCLUSIONS: Patients with the A1555G mutation generally present bilateral symmetrical sensorineural hearing loss, ranging from mild to moderate, slowly progressive, which is obvious approximately in the second decade of life and affects specially the high frequencies. Hearing loss severity is increased by treatment with aminoglycosides.

[Incidence of A1555G mutations in the mitochondrial DNA and 35delG in the GJB2 gene (connexin-26) in families with late onset non-syndromic sensorineural hearing loss from Cantabria]. / Incidencia de las mutaciones A1555G en el ADN mitocondrial y 35delG en el gen GJB2 (conexina 26) en familias con hipoacusia neurosensorial postlocutiva no sindrómica en Cantabria.

INTRODUCTION: Sensorineural deafness is a very common disorder in humans, which affects approximately 10% of the population. Genetic causes are suggested to be responsible for more than half of the cases. The A1555G mutation in the mitochondrial 12S rRNA gene and the 35delG mutation in the GJB2 gene are the most common mutations for sensorineural deafness in the Spanish population. METHODS: A genetic study was carried out in order to determine the frequency of the mutations A1555G in the mitochondrial DNA and 35delG in the connexin-26 gene in 21 patients from 21 non-consanguineous unrelated families affected by late-onset bilateral non-syndromic sensorineural hearing loss from Cantabria. RESULTS: The A1555G mutation was found in 6 patients. Five of these 6 patients had been treated with aminoglycosides. In all of them the auditory impairment affected mainly the high frequencies. The 35delG mutation was not found in any of the patients. CONCLUSIONS: The A1555G mutation in the mitochondrial DNA has been found to be the most common amongst the Cantabrian population. The A1555G mutation should be suspected in those members of families affected by sensorineural hearing impairment with a maternal inheritance pattern and ototoxicity from treatment with aminoglycoside antibiotics. The 35delG mutation in the GJB2 gene does not seem to be a major cause of deafness in families with late-onset non-syndromic sensorineural hearing loss in our area.