Aplicación de la técnica de árboles de clasificación y regresión en la valoración ecográfica de los nódulos tiroideos / Using Classification and Regression Trees in the ultrasound evaluation of thyroid nodules

Objetivo: Evaluar la capacidad de los árboles de clasificación y regresión (CART) en la valoración ecográfica de los nódulos tiroideos malignos. Materiales y métodos: Se realizaron 404 punciones aspiración con aguja fina (PAAF) a 384 pacientes. De los nódulos analizados, se registraron las características ecográficas (localización, tamano, morfología, contorno, consistencia, ecoestructura, ecogenicidad, calcificaciones y vascularización) y los resultados de la elastografía. Se aplicó el CART para investigar la relación entre los hallazgos ecográficos, la elastografía y el cáncer de tiroides. Resultados: El análisis CART determinó que la realización de una elastografía no aporta datos relevantes y que las zonas homogéneas pueden clasificar a los nódulos tiroideos en: 1.ª zona) caracterizada por ausencia de áreas de degeneración coloide e hipoecogenicidad asociada a malignidad; 2.ª zona) diferenciada por presencia de áreas de degeneración coloide combinada con ausencia de microcalcificaciones, constituyendo un indicador fiable de benignidad de los nódulos tiroideos; y 3.ª zona) la ausencia de hipoecogenicidad y una lesión menos alta que ancha deparan un indicador fiable de benignidad. El árbol de clasificación alcanzó una sensibilidad del 87,5% y un valor predictivo negativo del 98,8%. Discusión: El CART muestra una elevada capacidad de predicción de los nódulos malignos frente a otras técnicas lineales. Conclusión: La utilización de los árboles de clasificación provee una herramienta simple para la toma de decisión clínica con el objeto de reducir las PAAF innecesarias, con una elevada sensibilidad.

Objective: To evaluate the use of Classification and Regression Trees (CART) in the ultrasound evaluation of malignant thyroid nodules. Materials and methods: A study was performed on 404 fine needle aspirates (FNA), with biopsies being performed on 384. The information collected about the thyroid nodules was: ultrasound features (location, size, morphology, contour, consistency, echo-structure, echogenicity, calcification, and vascularisation) and elastography results. The CART technique was used to investigate the relationship between ultrasound findings and the thyroid cancer. Results: The CART analysis showed that elastography does not provide any relevant data, and that the homogeneous areas could classified the thyroid nodules into: 1st area) characterised by the absence of colloid degeneration areas and a hypo-echogenicity associated with malignancy; 2nd area) differentiated by the presence of colloid degeneration areas combined with absence of microcalcifications, constituting a reliable indicator of benign thyroid nodules; and a 3rd area) the absence of hypo-echogenicity and a lesion wider than it is long that provides a reliable indicator of being benign. The optimum tree produced a sensitivity of 87.5% and negative predictive value of 98.8%. Discussion: The CART technique demonstrated a high predictive capacity for malignant nodules compared to other linear techniques. Conclusion: The use of classification trees provides us with a simple tool for clinical decision making, in order to reduce unnecessary FNA biopsies, as well as achieving a high sensitivity.

Marcadores ecográficos de cromosomopatías en el I trimestre de lagestación: translucencia nucal / Ultrasound markers of chromosomal defects in the first trimester: nuchal translucency

El examen ecográfico detallado de la anatomía fetal permite detectar por un lado lasmalformaciones y por otro los marcadores ecográficos de cromosomopatías. Analizandoespecialmente a la translucencia nucal, que representa el grosor del espacio econegativolocalizado entre la piel y el tejido blando subcutáneo del embrión a nivel cervical, visualizadoentre las semanas 11 a 13+6 de gestación. Se debe utilizar un equipo de ultrasonografíacapaz de aumentar lo suficiente la imagen como para que la cabeza y la parte superior deltórax del feto ocupen el monitor y permita diferenciar medidas de hasta 0,1 mm, por víaabdominal o vaginal, situando los calipers en una posición dentro-dentro y evitando confundirla presencia del amnios como un valor alterado de la medida.La translucencia nucal se comporta como el marcador primario por excelencia en el Itrimestre del embarazo, en gestaciones únicas o múltiples, de bajo o alto riesgo genético, nosolo para discriminar las cromosomopatías, sino también por su importante asociación en fetoseuploides con mayor probabilidad de padecer malformaciones severas, sobre todo cardíacas.Sin embargo, la valoración óptima del riesgo incluye la consideración de otros factores, entreellos la edad materna, antecedentes familiares y marcadores bioquímicos.

Dermoscopic features of melanomas associated with MC1R variants in Spanish CDKN2A mutation carriers.

BACKGROUND: The presence of at least one MC1R gene variant is associated with a reduction in age at melanoma diagnosis in families with CDKN2A mutations. OBJECTIVES: To describe dermoscopic features of early melanoma in CDKN2A gene mutation-positive Spanish individuals and to evaluate the possibility of a correlation between particular dermatoscopic pattern and MC1R gene variants. METHODS: Patients in whom a melanoma was diagnosed during specific follow up of high-risk individuals carrying CDKN2A mutations (with familial or personal history of previous melanoma) were included in this study. The decision to remove such melanomas was taken on the basis of history, clinical and dermoscopic evaluations including total body photography and digital dermoscopy. RESULTS: Of the nine patients included in this study, three were noncarriers of the red hair MC1R polymorphism, three patients had one red hair MC1R polymorphism and three patients had two red hair MC1R polymorphisms. On dermoscopic analysis of suspect melanocytic lesions we found that the mean +/- SD ABCD total dermoscopy score (TDS) was significantly higher in noncarriers of red hair MC1R polymorphisms than in carriers of two MC1R gene red hair variants (6.8 +/- 0.4 vs. 4.4 +/- 0.9; P = 0.014). CONCLUSIONS: Early melanomas in patients with two MC1R red hair variants may be difficult to diagnose definitively by dermoscopy because, in our limited experience, they show fewer colours and structures and have a lower TDS. In such melanomas, subtle atypical vessels and other changes detected by digital image follow up may be useful to confirm the diagnosis of melanoma. An integrated approach including clinical history and dermoscopic data (also considering additional information, such as the presence of atypical vessels) should be utilized in evaluating these high-risk patients. Further studies are necessary to confirm our suggestion.

Marcadores ecográficos de cromosomopatías en el I trimestre de la gestación: ductus venoso / Ultrasound markers of chromosomal defects in the first trimester of pregnancy: ductus venosus

La evaluación Doppler del flujo en el ductus venoso en el primer trimestre ha venido a contribuir con información clínica relevante en las orientaciones a los padres. No sólo se mostró eficaz en el rastreo de anomalías cromosómicas, como la trisomía 21, disminuyendo la tasa de procedimientos invasivos, sino también en el rastreo de cardiopatías congénitas, redefiniendo el grupo de alto riesgo a ser sometido a ecocardiografía precoz. Por su parte, un flujo anormal en el ductus venoso asociado a la translucencia nucal aumentada en uno o en ambos fetos de un embarazo monocoriónico parece una combinación sensible para rastrear precozmente el síndrome de transfusión feto fetal. En todas estas situaciones, el ductus venoso se muestra un marcador eficaz de insuficiencia/disfunción cardíaca.

Doppler evaluation of the flow in the ductus venosus in the first trimester of pregnancy has contributed with clinical information relevant for parents counselling. Not only was effective in tracking chromosomal abnormalities such as trisomy 21, decreasing the rate of invasive procedures, but also in tracking congenital heart disease, redefining the high risk group to be subjected to early echocardiography. Also, an abnormal flow in the ductus venous linked to the nuchal translucency increased in one or both fetuses of a monochorionic pregnancy seem a sensitive combination to early trace the feto-fetal transfusion syndrome. In all these situations, the ductus venous shows to be an effective marker of cardiac dysfunction or insufficiency.

Dermoscopy of skin lesions in two patients with xeroderma pigmentosum.

BACKGROUND: Xeroderma pigmentosum (XP) is a rare disorder produced by a genetic defect in the repair of DNA damage caused by ultraviolet radiation. The early diagnosis of malignant skin tumours is crucial in the survival of patients with XP, but this is not easy even for experienced dermatologists due to the presence of a high number of actinic lesions. Dermoscopy is a new diagnostic method that increases the diagnostic accuracy for skin tumours. OBJECTIVES: To describe the clinical and dermoscopic features of different benign and malignant lesions [focusing on malignant melanoma, basal cell carcinoma (BCC) and benign melanocytic naevi] in two patients with XP. METHODS: Three dermatologists with experience in pigmented skin lesions and dermoscopy examined two siblings with XP over a period of 54 months. Diagnosis of skin tumours was obtained using clinical examination and dermoscopy with 10-fold magnification and digital images. All the tumours with criteria of malignancy were excised for further histopathological analyses. RESULTS: Multiple skin tumours showing some degree of pigmentation were detected in the patients. Clinical and dermoscopic examination allowed the discrimination of four melanomas (three of them in situ), 26 BCCs and five dysplastic naevi from other pigmented skin lesions. The features and parameters previously described for dermoscopy were shown to be appropriate for the recognition of tumours in our patients with XP. Generalized actinic lentigos were distinguished from BCCs by the presence of a delicate brown pigmented network. Fine vessels from poikiloderma were differentiated from the arborizing telangiectasia of BCC. CONCLUSIONS: The dermoscopic findings in the tumours were similar to those previously described in patients not affected by XP. Diagnosis by dermoscopic pattern analyses allowed a correct classification of malignant tumours in these cases.

Mouth-washings with recombinant human granulocyte-macrophage colony stimulating factor (rhGM-CSF) do not improve grade III-IV oropharyngeal mucositis (OM) in patients with hematological malignancies undergoing stem cell transplantation. Results of a randomized double-blind placebo-controlled study.

We investigated whether daily oral washings with recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) solution improved grade III-IV oropharyngeal mucositis (OM) in patients with hematological malignancies undergoing stem cell transplantation. Forty-one consecutive patients (21 males and 20 females, median age (range) 44 (16-69) years) were prospectively randomized to perform daily mouth-washes with either a 400 microg rhGM- CSF (Molgramostin, Schering-Plough) solution (group A, n = 18) or with a saline solution (group B, n = 23). Primary end-points were the intensity of OM, night rest quality and characteristics of food intake. Secondary end-points were need for and duration of parenteral nutrition, oral and intravenous analgesic requirements, incidence of viral or fungal oral infections and development of neutropenic fever. No differences were found between the placebo and rhGM-CSF-treated groups regarding overall duration of OM, maximum grade, reduction in at least one grade of OM (nine patients (56%) in group A vs 13 patients (68%) in group B), reduction of spontaneous or swallowing-induced pain, improvement in oral food intake, use of parenteral nutrition or use of systemic analgesics. In conclusion, mouth-washings with a 400 microg of rhGM-CSF solution do not improve severe OM in hematological patients undergoing stem cell transplantation.

Cancer mortality and exposure to chemical carcinogens in the work place: an ecological study in the Valencian Community, Spain (1981-1995).

To evaluate the geographical distribution of the mortality from malignant tumours in relationship with exposure to chemical carcinogens in the work place, and to asses the possible association between these questions and the percentage of population employed in certain high-risk sectors, an ecological study in the Valencian Community (VC), Spain was carried out. Age-adjusted mortality rates for the total number of malignant tumours, lung, bladder, lymphomas and leukaemia during the periods 1981-1985 and 1991-1995 were calculated for the 34 geographical areas. The percentage of population in each area working in sectors in which they may be exposed to chemical carcinogens was obtained. The relationship between mortality on-the-job exposure was studied using linear regression methods. Large differences in cancer mortality were seen. In men, the geographical pattern was very stable and reveals a significant association with the distribution of certain high-risk jobs. Statistically significant positive correlations (p < 0.001) were found between cancer mortality and the percentage of the population working in metal, wood and furniture sectors. In contrast, a negative and statistically significant (p < 0.001) correlation was observed between cancer mortality and the percentage of the population working in agriculture. In conclusion, although the variability in cancer mortality in men was significantly associated with some occupational sectors in the VC, caution is needed when drawing conclusions about causation from ecological studies.

Maternal nutritional factors: significance for the fetus and the neonate.

The nutrition of the gestating woman and of the lactating mother has always been a matter of concern and is frequently the object of pharmacological supplementation. During gestation and lactation, nutritional requirements undergo considerable changes. Studies based on nutritional surveys have shown that the diet of the gestating woman in Spain is deficient mainly in iron, folates, zinc and pyridoxin, with an excessive proportion of lipids. These nutritional habits change during gestation, particularly in the final months. The consumption of milk, particularly of semi-skimmed milk, has increased since 1989. Although pharmacological supplements may not be a valid alternative for all situations, they would be applicable in situations of high nutritional risk when the dietary contribution is insufficient. For the rest of the population, it is only necessary to obtain a supplement from a diet suitably enriched with vitamins and minerals.

Nocardia asteroides en absceso pulmonar interpretado como de origen tuberculoso: caso fatal / Nocardia asteroides in a pulmonary abscess considered to be of a tuberculous origin: fatal case

Se informa el hallazgo de cultivos puros de n. asteroides a partir de la colección purulenta obtenida por drenaje quirúrgico de un absceso en base pulmonar derecha, de 6 cm de diámetro, en una niña de 13 años de edad con desnutrición de segundo grado y antecedentes de tuberculosis. Lo prolongado de la evolución diagnóstica, el cuadro infeccioso inespecífico, y el probable deterioro inmunológico pudieron haber producido cierta demora en el diagnóstico y por lo tanto para el desenlace fatal

[Hepatic and renal changes in albino rats caused by the administration of chromium (VI) in drinking water]. / Alteraciones hepáticas y renales en rata albina por administración de cromo (VI) en agua de bebida.

The effects of sodium chromate administered in drinking water on liver and kidney of albino rats have been studied, through investigation of histological alterations and monitoring changes on serum urea levels and transaminases (GOT and GPT). Measurements have been done after 4, 8 and 12 weeks of treatment. The liquid intake of treated animals decreases with time. The amount of water drunk by treated rats is 1/2 of that drink by controls after 12 weeks. The histological alterations in liver and kidney are similar to those described elsewhere. Serum urea level is always higher in treated animals than in controls. GOT levels are similar in both treated and control rats, although always higher in the treated ones. GPT levels increase significantly after 12 weeks of treatment.

Natural occurrence of Nocardia in soil of Tucumán: physiological characteristics.

This is the first study initiated in Argentina to establish the presence of species of Nocardia from soil samples. These samples were gathered in different areas of Tucumán. Thirty three pathogenic strains of Nocardia were isolated by the paraffin bait method. Out of them, 28 were N. brasiliensis, 3 N. asteroides and 2 N. caviae. N. brasiliensis was widely distributed in the soil of the areas tested. It is proved that N. caviae, so rarely found in other regions of the world, occurs in Tucumán. A detailed study of the morphological and physiological characteristics for identification is discussed.

Relationships between the physiological characteristics and pathogenicity of Nocardia brasiliensis.

The analysis of 19 physiological properties of 28 strains of Nocardia brasiliensis isolated from soil reveal differences which could be of great value in distinguishing pathogenic from nonpathogenic strains.

Hexavalent chromium effects on motor activity and some metabolic aspects of Wistar albino rats.

The effects of hexavalent chromium on the motor activity and some metabolic aspects of albino rats were studied. 0.07 g Cr(VI)/l administered in drinking water produced no effects on the motor activity of rats, at least over 28 days of treatment. 0.7 g Cr(VI)/l in drinking water and 2 mg Cr(VI)/kg body wt injected i.p. significantly decreased the motor activity of rats after 7 days and 1 day, respectively. The treated rats showed a metabolic disadvantage in relation to the controls. The effects caused by Cr(VI) on the motor activity in rats could be an indication of the neurotoxicity of this metal.