[Review of the current value of ultrasonography in the characterization of thyroid nodules]. / Valor actual de la ecografía en la caracterización de los nódulos tiroideos. Revisión de las últimas guías clínicas de actuación.

The widespread use of medical imaging to study diseases of the neck reveals the prevalence of thyroid nodules can be as high as 67%. This is an important problem for the healthcare system because after analyzing the characteristics of the nodules a decision must be made regarding whether to perform fine-needle aspiration cytology to determine whether the lesion is malignant. In this article, we review the techniques for ultrasonographic study and fine-needle aspiration. We discuss the different guidelines for characterizing thyroid nodules and the criteria that help determine which patients need fine-needle aspiration for diagnosis and when an invasive procedure is unnecessary and can be avoided. Close collaboration with the different specialists involved in the management of thyroid nodules helps optimize resources and diagnostic performance.

[Diagnosis and differential diagnosis of liver abscesses using contrast-enhanced (SonoVue) ultrasonography]. / Diagnóstico y diagnóstico diferencial de abscesos hepáticos mediante ecografía con contraste (SonoVue).

OBJECTIVES: To describe the ultrasonographic findings in liver abscesses after the administration of a second generation agent. To perform the differential diagnosis of liver abscesses with other focal liver lesions. MATERIAL AND METHODS: We evaluated 28 liver abscesses in 5 patients before and after the administration of SonoVue. We also evaluated liver lesions in six patients in whom the differential diagnosis with liver abscess was considered in the baseline ultrasonographic examination. RESULTS: A typical enhancement pattern consisting of peripheral ring enhancement in the arterial phase and absence of central enhancement was observed in 21 (75%) abscesses. In another 6 (21.4%) abscesses, arterial enhancement was seen in large areas of the lesion, while other areas showed no uptake. One case (3.6%) had a multiseptated pattern of enhancement. Segmental hepatic enhancement was observed in 6 abscesses. In the liver lesions in which the differential diagnosis with abscess was carried out, 5 of the 6 showed no enhancement in any phase. The other lesion, a cystic metastasis, had irregular peripheral enhancement in the arterial phase. None of these lesions had segmental hepatic enhancement in the arterial phase. CONCLUSIONS: Contrast administration improves the performance of ultrasonography in the diagnosis of liver abscesses. There are three patterns of enhancement and these correlate well with the findings at CT and MRI. Contrast-enhanced ultrasonography is very useful for defining the internal architecture of the abscess, which is important for choosing the type of treatment. Contrast-enhanced ultrasonography also enables the differential diagnosis with other focal liver lesions.

Tumor fibroso solitario intraoral: análisis clinicopatológico e inmunohistoquímico / Intraoral solitary fibrous tumor: clinical, pathologic, and immunohistochemical analysis

El tumor fibroso solitario (TFS) es una neoplasia de partes blandascompuesta por células fusiformes, que principalmente se origina en lassuperficies mesoteliales. Generalmente tiene una localización intratorácica yla afectación de la cavidad oral es excepcional. Clínicamente el TFS intraoralsuele presentarse como una masa móvil, submucosa, no dolorosa, bien circunscrita,de lento crecimiento. El diagnóstico se obtiene mediante al análisishistopatológico e inmunohistoquímico. Histológicamente se caracterizapor una disposición variable de células fusiformes ovoides, generalmentepositivas para el marcador CD34. El tratamiento de elección es la extirpaciónquirúrgica de la lesión, recomendándose un seguimiento postoperatorio alargo plazo por la posibilidad de aparición de recurrencias y metástasis tardías.Presentamos un caso de TFS intraoral, localizado en el fondo del vestíbulomandibular. Un año después de la resección quirúrgica de la lesión, no haysignos de recidiva local o regional. Asimismo, realizamos una revisión de laliteratura(AU)

Solitary fibrous tumors (SFT) are spindle cell neoplasmsthat most often originate from mesothelial lined surfaces.Intrathoracic tumors are more common and oral mucosalinvolvement is uncommon. Clinically, intraoral SFT is usually apainless, well delimited, slow-growing, mobile submucosal mass.Diagnosis is based on immunohistochemical and histopathologicanalysis. Histologically, SFT is characterized by a variable provisionof spindle cells, which generally are CD34-positive. Resection is thetreatment of choice and long-term follow-up is recommended becauserecurrences and late metastases.We present a case of intraoral SFT of the mandibular vestibularsulcus. One year after surgical resection, there were no signs of localor regional recurrence. The literature was reviewed(AU)

Enfermedad de Wolman en dos hermanos / Wolman disease in two brothers

La enfermedad de Wolman (EW) es un raro trastorno metabólico por déficit de la lipasa ácida lisosomal. La evolución es fatal en el primer año de vida. Se presentan los casos de dos hermanos (con otros dos hermanos sanos entre ellos) hijos de padres consanguíneos. Ambos presentaron vómitos y estancamiento ponderal en la segunda semana de vida, así como hepatosplenomegalia y anemia progresivas. La tomografia computarizada mostró calcificaciones suprarrenales en el segundo paciente, pero no en el primero. La biopsia hepática del primer caso fue sugerente de EW. En el segundo se realizaron estudios de actividad enzimática que confirmaron el diagnóstico. Los pacientes fallecieron, en los primeros tres meses de vida (AU)

Encefalopatía por infección congénita por citomegalovirus / Encephalopathy due to congenital citomegalovirus infection

Introducción: La infección congénita por citomegalovirus (CMV) puede producir secuelas neurológicas. Presentamos tres casos de encefalopatía por CMV prenatal. Casos clínicos: todos los casos presentaron microcefalia, paresia espástica, déficit intelectivo, así como alteración del desarrollo cortical y calcificaciones cerebrales. Dos presentan hipoacusia y uno convulsiones. Un caso fue diagnosticado en el periodo neonatal, detectándose los otros dos por sintomatología neurológica progresiva. Conclusiones: la infección congénita por CMV debe considerarse en el diagnóstico etiológico de encefalopatía de causa no aparente (AU)

Hemorragia intraventricular neonatal pordéficit de factor V / Intraventricular hemorrhage in a newborn due to factor V deficiency

El déficit congénito de factor V es una rara coagulopatía autosómica recesiva cuya sintomatología suele aparecer tras el período neonatal. Se describe el caso de un neonato sin antecedentes patológicos obstétricos que presentó hemorragia intraventricular espontánea. El estudio de coagulación se encontraba alterado, encontrándose déficit grave de factor V. El estado de heterozigosis en padres se demostró al hallar concentraciones medias de factor V en ambos (AU)

[Factors associated with arterial distensibility in hypertension]. / Factores relacionados con la distensibilidad arterial en la hipertensión.

OBJECTIVE: To find out what variables affect changes in arterial compliance in subjects with hypertension by measuring their pulse wave velocity (PWV). DESIGN: Cross-sectional, descriptive study. SETTING: Rural health centre. PATIENTS: 156 hypertense patients under 76, chosen by simple random sampling from those on the hypertension register. MEASUREMENTS AND INTERVENTIONS: We determined the degree of hypertension, years of evolution, systolic pressure (SBP), diastolic pressure (DBP), body mass index (BMI), glucaemia, whether lipaemia existed, diabetes or glucose intolerance, tobacco habit, age, sex and PWV (measured automatically by computer). We performed multivariate analysis by means of multiple linear regression, with PWV as the dependent variable, and age, SBP, DBP, BMI, years of evolution of hypertension, cholesterol, triglycerides and glucaemia as independent variables. RESULTS: Mean age 62.5 (SD 8.8). 28.2% male. Mean SBP 153 (SD 18.9). Mean DBP 87 (SD 10.3). Mean years of evolution 10.4 (SD 7.4). Mean BMI 31.2 (SD 4.9). Hyperglucaemia 24.4%. Mean glucaemia 111.3 (SD 29). Mean PWV 11.82 (SD 2.37). PWV was above the theoretically normal figures in 69.2% of cases. Multiple linear regression showed that the variables which affected PWV significantly were age, SBP and hyperglucaemia. CONCLUSIONS: Arterial compliance can be improved by controlling SBP, given that the other related factors cannot be changed.

Factores relacionados con la distensibilidad arterial en la hipertensión / Factors relating to arterial compliance in hypertension

Objetivo. Averiguar qué variables influyen en las alteraciones de la distensibilidad arterial en los sujetos hipertensos mediante medición de la velocidad de onda de pulso (VOP). Diseño. Estudio descriptivo transversal. Ámbito. Centro de salud rural. Sujetos. Ciento cincuenta y seis pacientes hipertensos menores de 76 años, seleccionados por medio de muestreo aleatorio simple entre los incluidos en el registro de hipertensión arterial (HTA). Mediciones e intervenciones. Determinamos grado de HTA, años de evolución, tensión arterial sistólica (TAS) y diastólica (TAD), índice de masa corporal (IMC), glucemia, existencia de dislipemia, diabetes o intolerancia a la glucosa, hábito tabáquico, edad, sexo y VOP (medición automática por ordenador). Realizamos análisis multivariante mediante regresión lineal múltiple, siendo la variable dependiente la VOP y las independientes edad, TAS, TAD, IMC, años de evolución de la HTA, colesterol, triglicéridos y glucemia. Resultados. Edad media 62,5 (DE, 8,8); el 28,2 por ciento varones; TAS media, 153 (DE, 18,9); TAD media, 87 (DE, 10,3); media de años de evolución, 10,4 (DE, 7,4); IMC medio, 31,2 (DE, 4,9); hiperglucemia, 24,4 por ciento; glucemia media, 111,3 (DE, 29); VOP media, 11,82 (DE, 2,37). La VOP era superior a las cifras normales teóricas en un 69,2 por ciento. La regresión lineal múltiple mostró que las variables que influyen significativamente en la VOP son edad, TAS e hiperglucemia. Conclusiones. La mejora de la distensibilidad arterial puede obtenerse controlando la TAS, puesto que los otros factores relacionados son inmodificables (AU)

Compact residual structure in lentil lectin at pH 2.

Lentil lectin obtained from Lens culinaris collected in the La Armuña area (Salamanca, Spain) was examined by high-sensitivity differential scanning calorimetry, fluorimetry and measurements of circular dichroism at pH 2.0 and 7.4. At pH 2.0 the lentil lectin is not in the native state; however, at this pH it does show signs of a residual structure that breaks down upon heating. The lentil lectin at pH 2 shares some similarities with what has become known as the molten globule state. The thermal denaturation of intact (pH 7.4) and partially unfolded (pH 2.0) lentil lectin was irreversible and strongly dependent upon the scan rate, suggesting that its denaturation is under kinetic control. The process of lentil lectin denaturation is interpreted in terms of the simple kinetic model, Nk --> D, where k is a first-order kinetic constant that changes with temperature, as given by the Arrhenius equation; N is the native state, and D is the denatured state.

pH-dependent thermal transitions of lentil lectin.

The thermal stability of lentil lectin in the 5.0-10.0 pH range was studied by high-sensitivity differential scanning calorimetry and infrared spectroscopy. The thermally induced transitions for protein were irreversible and strongly dependent upon the scan rate at all pH values, suggesting that the denaturation is under kinetic control. It is shown that process of lentil lectin denaturation can be interpreted with sufficient accuracy in terms of the simple kinetic scheme, N-->D, where k is a first-order kinetic constant that changes with temperature, as given by the Arrhenius equation, N is the native state, and D is the denatured state. On the basis of this model, the parameters of the Arrhenius equation were calculated.

Thermal and pH-induced conformational changes of a beta-sheet protein monitored by infrared spectroscopy.

The stability of a lentil lectin, an all-beta protein, has been perturbed by changes in pH and temperature. In the pH interval 5.0 --> 10.0, the overall secondary structure does not undergo significant changes. However, if the individual components of the infrared amide I band are considered, changes in band components attributed to variations in beta-sheet and beta-turns cross-interactions are detected. The combined effects of pH and temperature reveal that the protein is more compact at pH 7.5 with lower denaturation temperatures at pH 5.0 or 10.0, indicating a less stable protein under those conditions. According to our results, the structural stability of the beta-sheet would depend not only on the intermolecular interactions among the strands but also on the conformation of the segments connecting these strands. The protein infrared band assignment has also been examined since the three-dimensional structure of the lentil lectin protein is known from X-ray diffraction studies. Two of the bands observed are attributed to beta-sheet. The one at 1620 cm-1, not affected if the medium is deuterated, is assigned to hairpins composed by two strands connected by a rigid turn whereas that located at 1633 cm-1 corresponds to strands associated by more flexible segments. The band appearing at 1645 cm-1 in H2O corresponds to the open, flexible loops that are connecting the beta-strands. The simplest assumption of the various secondary structure components having identical IR extinction coefficients is enough to provide IR-derived data that are in good agreement with the structure solved by X-ray diffraction.

Study of the influence of salt concentration on Newcastle disease virus matrix protein aggregation.

The aggregation process of Newcastle disease virus matrix protein (M protein) has been studied using light scattering. We observed that the aggregation of M protein is inversely correlated with ionic strength and that this process can be reversed by high salt concentrations. It was found that the oligomeric structure of NDV matrix protein is different from those described earlier for other matrix proteins of enveloped viruses.

Kinetic study on the irreversible thermal denaturation of lentil lectin.

The irreversible thermal denaturation of lentil lectin was investigated at pH 7.4 using different techniques including high-sensitivity differential scanning calorimetry, differential detergent solubility thermal gel analysis, intrinsic fluorescence and hemagglutinating activity assays. The shape of the transition, as well as its scan-rate dependence, can be explained by assuming that thermal denaturation takes place according to the kinetic scheme N k-->D, where k is a first-order kinetic constant that changes with temperature, as given by the Arrhenius equation, N the native state, and D the denatured one. On the basis of this model, the value of the rate constant as a function of temperature and the activation energy were calculated. The analytical data obtained with the other methods used in this work support the proposed two-state kinetic model.

Differential scanning calorimetry of the irreversible thermal denaturation of cellulase from Streptomyces halstedii JM8.

High-sensitivity differential scanning calorimetry has been applied to characterize the irreversible thermal denaturation of a cellulase, assuming that thermal denaturation takes place according to the kinetic scheme N-k-->D, where k is a first-order kinetic constant that changes with temperature, as given by the Arrhenius equation; N the native state, and D the denatured one. On the basis of this model, the values of the rate constant as a function of temperature and the activation energy were calculated. The analytical data obtained with the fluorescence method as well by measurement of the enzymatic activity temperature dependence support this two-state kinetic model.

[Ultrasound diagnosis in pediatrics]. / Diagnóstico por ultrasonidos en pediatría.

For many years, from the discovery of X-ray up today, medical morfological diagnosis has been based on the analysis of radiographic image. Having regard to the potential risks of ionizing radiations, radiological exploration can not be taken into account as they are harmful, and in some cases they can become dangerous. Authors point out that an abusive using of radiological exploration exists in our country. As for children, a negligent use of radiology can reach very concerned limits. Ultrasound systems which are currently available, used before radiology in a systematical manner, can resolve a morfological diagnostic in many cases, in a sure and faster way, with the great advantage to be a risk-less procedure because ultrasounds are mechanical not ionizing waves. Six cases are shown as an example of the diagnostic possibilities of ultrasound in pediatrics.