A hydrodynamic model of labyrinth to study the stimulation of perilymph compartments by audioprostheses.

CONCLUSIONS: The hydrodynamic model of the labyrinth spaces (LHM) is a useful tool for research on implantable audioprostheses, in particular to develop suitable actuators using MEMS technology (micro-electromechanic machine system). It has other potential applications for auditory research. OBJECTIVES: The energy reaching the labyrinth fluids is crucial information for developing prostheses to substitute the tympanic-ossicular system because adequate stimulation of the cochlear partition is essential. However, in vivo measurements in human ears are not currently available. Therefore a model of the normal labyrinth resembling its hydrodynamic properties becomes a valuable tool. It could allow comparison of different processing systems, algorithms and transducers, to develop new audioprostheses and improve their effectiveness and efficiency. MATERIALS AND METHODS: This work presents one LHM that emulates the conduction of the stimuli from the stapes footplate through the labyrinthine fluids, including its dimensions and physical properties, and some examples of measurements of perilymph stimulation by different audioprostheses and algorithms. RESULTS. As shown in the reported examples, this LHM provided effective measurement of acoustic stimulation across the whole human auditory frequency and intensity spectrum. Air-delivered and direct stimulation methods are possible. This provided convenient information for the actuator development and allowed comparison between different prototypes, stimulation patterns and algorithms.

Utilización de antidiabéticos en un área de salud urbana y otra rural de la provincia de Valencia / No disponible

Se realiza un estudio ecológico descriptivo de datos agregados de prescripción, cuyo objetivo es comprobarsi las distintas características sociodemográficas y asistenciales de un área de salud urbana y otra ruralcondicionan el uso de antidiabéticos.Material y métodos: El periodo de estudio abarca de enero de 2002 hasta diciembre de 2004. El consumo demedicamentos se expresa en dosis diaria definida por 1.000 habitantes y día estandarizada (DHD stand).Se realiza un análisis comparativo entre las dos áreas de salud de los subgrupos terapéuticos A10A, A10BA,A10BB, A10BG, A10BX y A10BF.Resultados: Al finalizar el periodo analizado, se aprecia un fuerte ascenso de la metformina, que a principios del periodo de estudio representaba, respecto al total de antidiabéticos orales (AO), el 11,2% en el área rural y el 15,3% en el área urbana, y en el último trimestre de 2004, el 24,4% en el área rural y el 24,6% en la urbana. El cociente insulinas/AO se mantuvo en el área urbana en 0,36-0,35, justo el doble que el valor0,18 del área rural.Conclusiones: El trabajo confirma que en un área rural el uso relativo de medicamentos antidiabéticoses mayor que en un área urbana y constata, en ambas áreas, un fuerte ascenso de la metformina, con unamayor adecuación a las guías de práctica clínica. Sin embargo, existe una menor utilización de insulina enel área rural, por lo que sería interesante realizar un estudio analítico posterior para confirmar la hipótesisde un uso insuficiente de insulinoterapia y/o excesivo de AO en el área rural

Objective: The authors performed a descriptive ecological study based on aggregate prescription data. The purpose was to determine whether the different sociodemographic characteristics and health care needs of an urban and a rural health area influence the use of antidiabetic agents.Material and methods: The study was carried out from January 2002 to December 2004. The consumptionof medications was expressed in standardized defined daily doses per 1000 population and day (standDDD). The two health areas were compared to determine the differences between therapeutic subgroups A10A,A10BA, A10BB, A10BG, A10BX andA10BF.Results: By the end of the study period, there was a marked increase in the prescription of metformin which,at the beginning of the study, had represented 11.2% of all oral antidiabetic agents consumed in the rural areaand 15.3% in the urban area. In the last quarter of 2004, these values were 24.4% in the rural area and 24.6%in the urban area. The ratio of insulin to oral antidiabetic agents in the urban area remained at 0.36-0.35,exactly twice that of the rural area, where it was 0.18.Conclusions: This study confirms the fact that, in the rural area, the relative use of antidiabetic agentsis greater than in the urban area, and demonstrates, in both areas, a marked increase in the prescriptionof metformin, with a greater adaptation to the clinical practice guidelines. However, insulin is less widelyadministered in the rural area. For this reason, it might be of interest to carry out a subsequent analyticalstudy to confirm the hypothesis concerning the underutilization of insulin therapy and/or overuse of oral antidiabetic agents in the rural area.

Intoxicaciones accidentales en niños en el Hospital General de Requena (1997-2002) / Accidental poisoning of children at Requena General Hospital (1997-2002)

No disponible

Evaluación del sistema de recepción de medicamentos en un área de gestión centralizada / Evaluation of a system of medicines reception in a centralized management area

Fundamento. Evaluar el sistema de recepción en el Área de Gestión de Medicamentos (AGES), mediante la implantación de la hoja de gestión de problemas (HOPRO), y del establecimiento de criterios explícitos de calidad de procesos y de resultados. Métodos. Se analizan retrospectivamente 136 HOPRO generadas durante 3 meses. Los problemas de recepción identificados se clasifican en función de sus causas más inmediatas, calculando el tiempo medio necesario para su resolución. Por último se averigua el grado de cumplimiento de los criterios y estándares de calidad establecidos para esta actividad. Resultados. A través de la HOPRO se registran, clasifican y valoran los problemas de recepción de medicamentos en el AGES. Se confirma que este documento genera un circuito de trabajo que permite coordinar las funciones del personal del AGES (evitando errores), y la trazabilidad de los procesos. Asimismo, se establecen criterios y estándares de calidad de proceso y de resultado relacionados con la fase de recepción, observándose que existe un grado de cumplimiento inferior al 40 por ciento en los criterios relacionados con el tiempo necesario para la resolución de problemas. Conclusiones. Se valida la HOPRO como documento que registra problemas y facilita su seguimiento y evaluación final. Se desprende una oportunidad de mejora en cuanto al tiempo requerido para resolver problemas de recepción, poniendo de manifiesto la necesidad de incorporar canales de comunicación más eficaces entre el Servicio de Farmacia y proveedores, así como la informatización y automatización de procesos, para aumentar la seguridad y eficiencia en el trabajo. (AU)

The crystalline pattern of calcium in different topographical regions of the otoconial membrane. An electron probe and spectroscopic diffraction study.

Quantitative electron probe microanalysis and electron spectroscopic diffraction analysis was used to determine the gradient of distribution of calcium and its crystalline pattern at different levels (lower gelatinous membrane, upper gelatinous membrane and otoliths) in the otoconial membrane of adult OF1 mice. Our quantitative electron probe microanalytical data, obtained with scanning-transmission electron microscopy, indicated that there was a gradient in calcium concentration which increased from the vestibular surface towards the otoliths. Differences between the three regions of the otoconial membrane were statistically significant in both the utricle and saccule. Our results with electron spectroscopic diffraction revealed an increasing crystalline development from the lower gelatinous membrane towards the otoliths. Our findings with both techniques suggest that the gelatinous membrane is involved in the maturation and crystallization of the otoliths.

[Late p53 mutation in head and neck oncogenesis]. / La mutación p53: un fenómeno tardío en la oncogénesis de cabeza y cuello.

p53 mutation are currently recognized as the commonest genetic event in human tumors. In this paper are studied, through immunochemistry, the p53 protein expression of 25 carriers from squamous cell carcinoma of the larynx and hypopharynx as well in the non tumoral mucosa of the larynx removed and corresponding metastases. Because of the great overexpression of this protein among tumors and its metastases, aside with the low expression in normal far-off mucous membranes of the studied growths, the AA. draw out the conclusion that p53 mutation is a late event by neck and head oncogenesis.

[Morphological and functional correlations of the protective action of coenzyme A in cisplatin ototoxicity (II)]. / Correlaciones morfofuncionales de la acción protectora del coenzima A en la ototoxia por cisplatino (II).

Earlier studies have shown that coenzyme A (CoA) protects against cisplatin (CP) induced deafness in guinea pigs. We studied the correlation between the latency of the N1 wave in electrocochleography and total loss of cilia in hair cells by scanning electron microscopy.

[Expression of proto-oncogene bcl-2 in squamous cell carcinoma of the larynx]. / Expresión del proto-oncogén bcl-2 en el carcinoma epidermoide de laringe.

Apoptosis, or programmed cell death, is responsible for deleting cells in normal tissues to maintain homeostasis after DNA damage. Apoptosis has several physiological inhibitors, one of the most important being the proto-oncogene bcl-2. An immunohistochemical study was made of bcl-2 expression in 25 squamous cell carcinomas of the larynx, in laryngeal mucosa distant from the primary neoplasm, and in lymph node metastases. The relationship between bcl-2 expression and various clinical and pathological parameters was investigated. Bcl-2 was detected in 40% of primary tumors and in 71% of lymph node metastases; it seems to be a late event in laryngeal malignant transformation. We found no statistical association between bcl-2 expression and most of the clinical and pathological parameters examined. Only tumor differentiation was related to bcl-2 expression, bcl-2 positive tumors being moderately or poorly differentiated (p < 0.02).

[AIDS manifestations in otorhinolaryngology]. / Manifestaciones del SIDA en otorrinolaringología.

The otorhinolaryngological signs of AIDS are reviewed (both analysis and synthesis) following the chronological order of the literature. The earliest clinical pictures, their frequency and time of onset, are described by the authors studied. In 1986 the ENT signs of this disease were well known, and in our region the same multiple, polyfacetic aspects are seen. Personal experience of this is described, emphasizing how seldom the diagnosis has been made, except early on. Usually the cases seen and diagnosed by the Department of Infectious Diseases were referred for specialist opinion. The commonest findings were, amongst the opportunist infections: oropharyngeal and oesophageal candidiasis, and tuberculous adenopathies. Classical ENT pathology was represented by sinusitis and to a lesser extent by otitis and tonsillitis. The tumours seen were non-Hodgkin lymphomas, but no Hodgkin's or Burkitt's lymphomas. There was an unusual case of 'high grade centroblastic lymphoma', localized to the tonsil and presenting as necrotic tonsillitis and peritonsillar abscess. Recently a patient with a large pharyngeal tumour (still being investigated) has been provisionally diagnosed as having a cavernous angioma. Both these patients were diagnosed by us, since we saw the first sign of the disease. We have seen few Kaposi's sarcomas, since cutaneous and oral lesions are not usually referred to us.

Spectrophotometric determination of the theophylline in plasma by the apparent content curves method.

A direct spectrophotometric procedure for the determination of theophylline in plasma is proposed. This procedure is based on the apparent content curves method and it is not necessary to know the nature and contents of interferent substances. Bias errors introduced by plasma and metabolites are avoided. The results obtained are in agreement with those provided by an immunofluoroassay used as a reference method.

Pantothenic acid and coenzyme A in experimental cisplatin-induced ototoxia.

We have observed that pantothenic acid (PA) prevents deafness induced by cisplatin (CP) in the guinea pig if both drugs are administered jointly. When deafness was previously produced, recovery was sometimes obtained after the administration of PA; so, we studied the effects of PA on cisplatian-induced ototoxia in guinea pigs, both as a prophylactic agent in healthy animals, and as a therapeutic agent in animals previously made deaf by the drug. To elucidate why PA protects the ear from the toxic effects of CP, we used coenzyme A (CoA) instead of PA-since PA is a component of CoA-to test the hypothesis that the action of PA is due to CoA. The results were practically the same in both experiences, the compound action potential of the auditory nerve (CAP) was tested and cochleas were examined by scanning electron microscopy (SEM). Our results suggest that the protective effect of PA takes place through CoA. Both substances had the same effect on CP ototoxicity, but CoA appears to be much more active, since the dose tested here was much lower than that of PA.

[A CT cytomorphodensitometric study of the proliferating epithelial activity in middle ear cholesteatoma]. / Estudio citomorfodensitométrico por análisis de imagen de la actividad proliferativa epitelial en el colesteatoma de oído medio.

A cytomorphodensitometric study was made by analysis of the computerised image of the germinative and intermediate epithelial layers in a sample of five specimens of cholesteatoma and the corresponding skin from the external auditory canal. A morphometric variable corresponding to the nuclear area was determined and densitometric variables equivalent to the relative quantity of nuclear DNA were determined. Within the germinative layers of the cholesteatoma epithelium, we observed larger nuclei and more relative DNA per nucleus. The average densitometric values were in the range of 2C-4C, which is indicative of a greater cellular population in S phase in the cholesteatoma than in the skin.

[The study of proliferative epithelial activity in cholesteatoma of the middle ear during cytomorphophotometry]. / Estudio de la actividad proliferativa epitelial en el colesteatoma de oído medio mediante citomorfofotometría.

Epithelial proliferation in colesteatoma and its influence on the subepithelial inflammatory reaction was studied using morphometry and nuclear photometry of specimens. Twenty specimens of colesteatoma and 15 specimens of skin from the external auditory canal were examined. Nuclear content was greater in the basal cells of colesteatoma epithelium than in the basal cells of external auditory canal epithelium, suggesting increased proliferative activity. This activity was found to be reted to the inflammatory infiltrate of the conjunctive tissue and varied in different specimens.

Early morphofunctional alterations induced by cisplatin in the cochlea. A quantitative and electrocochleographic study.

The early morphological and functional alterations of the cochlea were studied in guinea pigs treated with cisplatin, administered to two groups of animals as a single dose of 4 or 10 mg/kg body weight. Morphological changes were observed by scanning electron microscopy, and functional alterations were investigated by electrocochleography to record compound action potentials. Statistically significant alterations in neurosensory stereocilia, consisting of partial or total denudation, were observed only after the experimental administration of the higher dose of cisplatin; these changes were consistently associated with distortions in the compound action potential.

Changes in immunologic response in tonsillectomized children. I. Immunosuppression in recurrent tonsillitis.

The possible immunoregulatory role of the tonsils was studied by determining immunoglobulins IgG, A, M, E and factors C'3, C'4 and PFB of the complement system before and after tonsillectomy. The synthesis in vitro of IgG and IgM by lymphocytes stimulated with pokeweed mitogen was also measured. There were statistically significant differences between pre and post-operative levels of serum IgG, IgA and IgM, which decreased after surgery. Practically no change in the mean values of IgE and no significant differences in the levels of serum C'3, C'4, and PFB, were found. The in-vitro synthesis of both immunoglobulins (IgG, IgM) by lymphocytes increased significantly after tonsillectomy. Our results suggest that not only does tonsillectomy have no counterproductive effect on the immune system, but that, on the contrary, it seems to improve the immune response, since it appears to unblock the suppression to which the immune system was subject.

Effects of renal insufficiency on the cochlear absorptive-secretory areas. A morphological study in the Mongolian gerbil.

In order to evaluate the effects of experimental renal insufficiency (RI) on the labyrinthine absorptive-secretory areas (ASA), 54 adult Mongolian gerbils were submitted to bilateral nephrectomy or to sham procedure. At different intervals (3, 6, 9, 12, 15, 18, 21, 24 hours) after the surgical procedures, or during the terminal stage (28 h) the animals were decapitated and both temporal bones were dissected to obtain selected specimens of the cochlear ASA. The specimens were processed and analysed by light and electron microscopy. Structurally, RI induced progressive thickening of the epithelial components (stria, prominentia, sulcus); separation by fluid accumulation between stria and mesodermal layer; and frequent dilatation of intraepithelial vessels. Ultrastructurally, diverse signs were observed parallel to the evolution of the RI. After 12 h a progressive enlargement of the intercellular spaces, which was particularly evident in the stria surrounding the vessels and in the other sulcus, was observed. Its latest expression was a marked widening of the basolateral spaces containing a granular substance. After 12 h the formation of large cytoplasmic perinuclear spaces containing small rounded vesicles, probably secondary to fluid accumulation, could be observed in the marginal cells. After 24 h diverse signs of organellar damage became evident (schedule: mitochondrial swelling, lysosome like figures, myelin like figures). In the terminal stage, a general homogenization of the cytosol was common. The findings suggest a definite re-distribution of fluids in the inner ear. A close relationship between renal dysfunction and labyrinthine microhomeostasis is therefore proposed.