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Resumen Las neoplasias en glándulas salivales son infrecuentes, representando menos del 3% de los tumores de cabeza y cuello. El carcinoma mucoepidermoide es el tumor maligno más común en glándulas salivales, siendo su principal ubicación la parótida. Clínicamente se asemeja a otras lesiones de mucosa oral, por lo cual, es importante realizar un correcto diagnóstico diferencial. Su comportamiento biológico se relaciona con el grado histológico tumoral, factor relevante en el pronóstico y tratamiento de esta neoplasia. Presentamos el caso de un paciente hombre de 75 años afectado con un tumor en paladar con diagnóstico de carcinoma mucoepidermoide de bajo grado. Como tratamiento se realizó una maxilectomía parcial y una placa obturadora en base a una prótesis removible y posterior reconstrucción con un colgajo libre microvascularizado. Actualmente el paciente se encuentra en controles periódicos, libre de enfermedad. Los tumores de glándulas salivales son un desafío diagnóstico, requieren de exámenes imagenológicos y del estudio histopatológico. Cuando existen dudas en el diagnóstico, se debe considerar repetir la toma de la muestra o la obtención de biopsias de más de una zona representativa que permita el diagnóstico de la lesión.

Abstract Salivary gland neoplasms are infrequent lesions representing less than 3% of head and neck tumors. Mucoepidermoid carcinoma is the most common malignant tumor in salivary glands, being the parotid the most usual location. Clinically, it resembles other oral mucosa lesions, therefore, it is important to make a correct differential diagnosis. Its biological behavior is related to the tumor histological grade, a relevant factor in the prognosis and treatment of this neoplasm. We reported a case of a 75-year-old-man, with a tumor in the palate, diagnosed as low-grade mucoepidermoid carcinoma. A partial maxillectomy and an obturator plate were performed based on a removable prosthesis and subsequent reconstruction with a microvascularized free flap. The patient is currently undergoing regular checkups, maintaining disease free. Salivary gland tumors are a diagnostic challenge, requiring imaging tests and histopathological study. In case of doubts with the diagnosis, it should be considered to biopsy more than area or to repeat the biopsy in order to obtain a representative sample that allows the diagnosis of the lesion.

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Nitrofurans (5-nitro-2-hydrazonylfuran as pharmacophore) are a group of widely used antimicrobial drugs but also associated to a variety of side effects. The molecular mechanisms that underlie the cytotoxic effects of nitrofuran drugs are not yet clearly understood. One-electron reduction of 5-nitro group by host enzymes and ROS production via redox cycling have been attributed as mechanisms of cell toxicity. However, the current evidence suggests that nitrofuran ROS generation by itself is uncapable to explain the whole toxic effects associated to nitrofuran consumption, proposing a nitro-reduction independent mechanism of toxicity. In the present work, a series of nitrated and non-nitrated derivatives of nitrofuran drugs were synthesized and evaluated in vitro for their cytotoxicity, ROS-producing capacity, effect on GSH-S-transferase and antibacterial activity. Our studies showed that in human cells non-nitrated derivatives were less toxic than parental drugs but, unexpectedly preserved the ability to generate intracellular ROS in similar amounts to nitrofurans despite not entering into a redox cycle mechanism. In addition, some non-nitrated derivatives although being uncapable to generate ROS exhibited the highest cell toxicity among all derivatives. Inhibition of cytosolic glutathione-S-transferase activity by some derivatives was also observed. Finally, only nitrofuran derivatives displayed antibacterial effect. Results suggest that the combined 2-hydrazonylfuran moiety, redox cycling of 5-nitrofuran, and inhibitory effects on antioxidant enzymes, would be finally responsible for the toxic effects of the studied nitrofurans on mammalian cells.

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Understanding the molecular interactions that rule the physicochemical properties of molecular assemblies is of particular interest when trying to explain the behavior of much more complicated systems, such as the cell membranes. This work was devoted to study a discotic nematic lyotropic liquid crystal, formed by sodium dodecylsulphate (3% SDS-d25) and decanol (20% DeOH-α-d2), dissolved in aqueous solutions (0.1% D2O) of Na2SO4 or Li2SO4. The average size of the aggregates was estimated using fluorescence quenching experiments, and their dynamics were studied by measuring the (2)H-NMR quadrupole splitting (ΔνQ) and the longitudinal relaxation times (T1) of the deuterated species. To provide an atomic insight into these assemblies, molecular dynamics simulations of the systems were carried out with atomic detail. As a previous step in this study, a reparameterization of the standard GROMOS 87 force field was required to perform the equilibrated simulations and to prevent instabilities emerging during the simulations. Finally, an excellent agreement between simulation and experimental data was obtained. In addition, variations in the long range electrostatic interactions at the aggregate/solution interface, the orientation and the reorientational relaxation time of the water dipole, the translational diffusion coefficient of sodium ions, and the amphiphile-counterion coordination associated with the presence of Li(+) in the solution were other key aspects investigated to explain the variation in the quadrupole splittings (ΔνQ) in the presence of lithium in solution.

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Poultry is a main reservoir and source of human infection in campylobacteriosis. Three hundred and forty one stool samples (291 human, 50 avian) were analyzed. In the human group, 220 samples were collected from children with acute diarrheal disease (183 inpatients, 37 outpatients) and 71 from healthy children. Erythromycin and ciprofloxacin agar dilution MIC tests, Penner serotyping and RAPD-PCR genotyping were performed on 23 strains isolated. C. jejuni was reported only in patients with acute diarrhea (5.4 percent inpatients, 2.2 percent outpatients). Campylobacter prevalence in poultry was 34 percent. Cross-resistance to nalidixic acid and ciprofloxacin was found in 33.3 percent of human samples and 11.8 percent of animal samples. Human samples could not be typed using the Penner method. F serotype was the most expressed in poultry. We obtained a total of 14 genotypes (4 / 5 human and 10/15 avian). In conclusion, the predominant species in poultry and humans was C. jejuni, a significant amount of quinolone-resistant human and avian samples were obtained, and avian genotypes and serotypes were not found in human samples. The latter would mean that another source of infection could exist; therefore other reservoirs must be studied.

Las aves de consumo constituyen uno de los principales reservorios y fuente de infección humana de la campilo-bacteriosis. Se analizaron 341 muestras de deposiciones, 291 humanas y 50 aviares. De las muestras, 220 de niños con síndrome diarreico agudo-SDA (183 hospitalizados y 37 consultantes ambulatorios) y 71 niños sanos. A las 23 cepas obtenidas se les realizó CIM por dilución en agar a eritromicina y ciprofloxacina, serotipificación de Penner y genotipiicación por RAPD-PCR. Se encontró Campylobacterjejuni sólo en pacientes con SDA, de ellos 5,4 por ciento ambulatorios y 2,2 por ciento hospitalizados. En aves, la prevalencia de Campylobacter spp., fue de 34 por ciento. Hubo resistencia cruzada a ácido nalidixico y ciprofloxacina en 33,3 por ciento cepas de origen humano y 11,8 por ciento animal. Las cepas humanas fueron no tipiicables por el método de Penner. Predominó entre las aves el serotipo F. Se obtuvo un total de 14 genotipos (4/5 humanos y 10/15 aviares). En conclusión, la especie predominante en aves de corral y en humanos fue C. jejuni, existiendo una alta prevalencia de cepas de origen humano y aviar resistentes a quinolonas. Los genotipos y serotipos aviares no fueron encontrados en cepas de origen humano, lo que indica que podría existir otra fuente de infección, por lo que se requiere estudiar otros reservorios.

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Poultry is a main reservoir and source of human infection in campylobacteriosis. Three hundred and forty one stool samples (291 human, 50 avian) were analyzed. In the human group, 220 samples were collected from children with acute diarrheal disease (183 inpatients, 37 outpatients) and 71 from healthy children. Erythromycin and ciprofloxacin agar dilution MIC tests, Penner serotyping and RAPD-PCR genotyping were performed on 23 strains isolated. C. jejuni was reported only in patients with acute diarrhea (5.4% inpatients, 2.2% outpatients). Campylobacter prevalence in poultry was 34%. Cross-resistance to nalidixic acid and ciprofloxacin was found in 33.3% of human samples and 11.8% of animal samples. Human samples could not be typed using the Penner method. F serotype was the most expressed in poultry. We obtained a total of 14 genotypes (4 / 5 human and 10/15 avian). In conclusion, the predominant species in poultry and humans was C. jejuni, a significant amount of quinolone-resistant human and avian samples were obtained, and avian genotypes and serotypes were not found in human samples. The latter would mean that another source of infection could exist; therefore other reservoirs must be studied.

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To determine clinical and epidemiological features of scorpion stings in two departments of Colombia, a descriptive study was performed in the hospitals of 10 towns from Antioquia (2 256 071 inhabitants) and five from Tolima (630 424 inhabitants). One hundred and twenty-nine cases were admitted during one year, 51 in Antioquia, 78 in Tolima and 41 were children less than 15 years old. Most stings (70.5%) occurred inside the house; 27.9% were on the hands and 26.4% on the feet. The scorpion species involved were Tityus pachyurus (51), Centruroides gracilis (31), T. fuehrmanni (29), T. asthenes (7) and Chactas spp. (1). In 10 cases the scorpion involved was not identified. Systemic envenoming signs (e.g. vomiting, tachypnea) were significantly more frequent in children than in adults (P < 0.05). Four children had hypertension, but none developed pulmonary oedema. One 3-year-old girl, stung by T. asthenes, had acute oedematous pancreatitis. Ninety-eight patients had mild envenoming. Moderate (27 patients) and severe (four patients) envenoming was significantly more frequent in children than in adults (P = 0.003; relative risk = 2.97). A pepsin-digested anti-Centruroides spp. antivenom was administered to 19 of 31 patients presenting systemic envenoming signs. No adverse reactions to antivenom were observed.

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The structure and aggregation number of a discotic lyotropic liquid crystal, prepared from tetradecyltrimethylammonium chloride (TDTMACl)/decanol (DeOH)/NaCl/H2O, have been examined using fluorescence quenching of pyrene by hexadecylpyridinium chloride and molecular dynamics (MD). The fluorescence method gives an aggregation number of 258 +/- 25 units (DeOH + TDTMACl). From the MD simulation, a lower limit for the aggregate dimension of 130 units of DeOH + TDTMACl is predicted. A stable oblate aggregate of 240 units was studied in detail. A strong polarization between the ammonium headgroups and chloride ions is observed from the calculated trajectory. DeOH headgroups are located, on average, 0.3 nm more to the interior of the aggregate than the TDTMACl headgroup and contribute to widening the interface by forming H-bonds with water. The radial distribution function of the ammonium headgroup shows that there are 16 water molecules in the first solvation sphere. The diagonal elements of the order parameter tensor of the tail atoms of both surfactants indicate that the interior of the micelle preserves about the same degree of order as at the interface, up to the last three atoms of the aliphatic chain, where the order starts to decrease.

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Fine's severity prediction index (SPI), was retrospectively analyzed in community acquired pneumonia (CAP), in patients at Concepción Regional Hospital, from June to August 2000. We studied 57 CAP patients: 23 as low risk and 34 as high risk patients. In comparison to low risk patients the main features of high risk patients were: older age (p < 0.00001), higher comorbility (p < 0.004), longer hospitalization (p < 0.0007) and higher mortality (p < 0.018). Mortality in low risk patients was similar to Fine's study: 4.3 versus 3.5%. In high risk patients mortality was 26% versus 38%. Main complications in our series were mechanical ventilation (43.8%), PaO2/FiO2 < 250 mmHg (43.8%), and hepatic coma (38.5%). As a conclusion, we recommend the use of SPI in CAP at Emergency Services in order to better evaluate mortality, optimizing criteria of hospital admission.

Se evaluó el Índice de Gravedad de Fine (IG) en neumonías de la comunidad (NAC) hospitalizadas en el Hospital Regional de Concepción en trabajo retrospectivo con 57 casos entre Junio y Agosto del año 2000. Se estudiaron 23 pacientes catalogados de bajo riesgo y 34 de alto riesgo. Características de alto riesgo fueron, mayor edad (p < 0,00001), mayor comorbilidad (p < 0,0004), estadía prolongada (p < 0,00007) y mayor mortalidad (p < 0,018). La mortalidad de bajo riesgo fue similar a la de Fine, 4,3% versus 3,5%, siendo menor en el grupo de alto riesgo, 26% versus 38%. Factores de mayor complicación en NAC fueron, ventilación mecánica (43,8%), PaO2/FiO2 < 250 mmHg (43,8%) y coma hepático (35,8%). Conclusión: es aconsejable el uso del IG en NAC a nivel de Servicios de Urgencia, para evaluar los riesgos de mortalidad, optimizando así los criterios de ingreso al hospital.

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Se revisaron 182 fichas de pacientes amputados durante los años 1990 a 1992 en el Hospital del Trabajador de Santiago, registrándose variables sociodemográficas, tipo de accidente, diagnóstico psiquiátrico y situación psicosocial. Se realizó una entrevista de seguimiento a 130 de esos pacientes 5 a 7 años después del accidente aproximadamente. Los diagnósticos más frecuentes fueron las reacciones de ajuste ansioso (33 por ciento) y mixtas (19 por ciento). El 87 por ciento se encuentra trabajando con buen nivel de satisfacción y el 90 por ciento se siente apoyado por su familia. El 42 por ciento presenta dolor fantasma que se relaciona con altos niveles de angustia y depresión y con el nivel de amputación. También el 42 por ciento muestra franca disminución de la actividad social. Se encontraron elevados índices de angustia y depresión en la muestra

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