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BACKGROUND: The origin of melanoma has always been a debated subject, as well as the role of adjacent melanocytic naevi. Epidemiological and histopathological studies point to melanomas arising either de novo or from a naevus. OBJECTIVES: To evaluate the presence of mutations in genes from well-known melanomagenesis pathways in a large series of naevus-associated melanomas. MATERIALS AND METHODS: Sixty-one melanomas found in association with a pre-existing naevus were microdissected, after careful selection of cell subpopulations, and submitted to Sanger sequencing of the BRAF, NRAS, c-KIT, PPP6C, STK19 and RAC1 genes. Each gene was evaluated twice in all samples by sequencing or by sequencing and another confirmation method, allele-specific fluorescent polymerase chain reaction (PCR) and capillary electrophoresis detection or by SNaPshot analysis. Only mutations confirmed via two different molecular methods or twice by sequencing were considered positive. RESULTS: The majority of cases presented concordance of mutational status between melanoma and the associated naevus for all six genes (40 of 60; 66.7%). Nine cases presented concomitant BRAF and NRAS mutations, including one case in which both the melanoma and the adjacent naevus harboured V600E and Q61K double mutations. In two cases, both melanoma and associated naevus located on acral sites were BRAF mutated, including an acral lentiginous melanoma. CONCLUSIONS: To our knowledge this is the largest naevus-associated melanoma series evaluated molecularly. The majority of melanomas and adjacent naevi in our sample share the same mutational profile, corroborating the theory that the adjacent naevus and melanoma are clonally related and that the melanoma originated within a naevus.

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INTRODUCTION: Tetrapterys mucronata Cav. (Malpighiaceae) is a plant used in some regions of Brazil in the preparation of ayahuasca. OBJECTIVE: To determine the content of the main tryptamine alkaloids in the stem bark of T. mucronata Cav. and assess their possible toxic and hallucinogenic properties based on the doses found in a water decoction that mimics the ayahuasca preparation. METHODS: Four alkaloids previously described for their toxic and hallucinogenic properties were quantitated by multiple reaction monitoring HPLC combined with electrospray ionisation and tandem MS (HPLC-ESI/MS/MS) in the water decoction and ethanolic extracts from the bark of T. mucronata. RESULTS: Exhaustive extraction of the stem barks with ethanol revealed the following alkaloid levels: bufotenine (1) 3.26 ± 0.31 mg/g, 5-methoxy-N-methyltryptamine (2) 0.88 ± 0.08 mg/g, 5-methoxy-bufotenine (3) 3.07 ± 0.22 mg/g and 2-methyl-6-methoxy-1,2,3,4-tetrahydro-ß-carboline (4) 0.14 ± 0.004 mg/g. The water decoction presented slightly lower levels, ranging between 2.32 ± 0.14, 0.50 ± 0.04, 1.53 ± 0.09 and 0.10 ± 0.01 mg/g for (1), (2), (3) and (4) respectively. CONCLUSIONS: The HPLC-ESI/MS/MS quantitation revealed significant alkaloid levels, in particular for bufotenine and 5-methoxy-bufotenine. As such compounds are known for their toxic and hallucinogenic properties, these results indicate that the consumption of this plant as an ingredient in ayahuasca preparations may present a risk to consumers.

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Triatomines (Hemiptera, Reduviidae) are bloodsucking insects involved in the transmission of Trypanosoma cruzi, the causative agent of Chagas disease, an important public health problem in Latin America. The triatomine species found in sylvatic habitats generally play a limited epidemiological role compared to domestic species, but they may act as a reinfestation source of dwellings after insecticide spraying and have to be carefully considered in control strategies of Chagas disease transmission. The objectives of this work were to carry out a survey of the sylvatic triatomine species colonizing Furnariidae nests in a typical area of the Chaco region of Argentina during the winter and to study the parasites and natural enemies associated with the collected triatomines. Sixty-three triatomine specimens were collected from Furnariidae nests (Coryphistera alaudina and Phacellodomus sibilatrix) randomly selected within the study area. Fifty-four were identified as Psammolestes coreodes, seven as Triatoma platensis, and two as Triatoma infestans. Specimens of T. infestans and T. platensis were found in one nest. The first finding of instar nymphs of T. infestans x T. platensis in a sylvatic habitat is reported. For the first time, sylvatic collected specimens of T. platensis were found infected by T. cruzi. Triatoma virus was found in one Ps. coreodes specimen.

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Objetivos. Aunque clásicamente se consideraba que era poco frecuente, en los últimos años se ha observado que existe una mayor frecuencia de onicomicosis en pacientes con lesiones psoriásicas de las uñas. El objetivo de este estudio ha sido valorar si entre los pacientes que consultan por onicomicosis existe una proporción de pacientes con psoriasis mayor de la esperada y si existen diferencias en la forma clínica de presentación de la onicomicosis. Diseño. Estudio post hoc a partir de dos registros epidemiológicos sobre pacientes diagnosticados clínicamente de onicomicosis. Emplazamiento. Asistencia Primaria (AP) y servicios de dermatología (DER) durante el año 2004 en Barcelona. Participantes. Las muestras recogidas fueron de n =1.051 y n = 1.906, respectivamente. Mediciones principales. Las características clínicas estudiadas fueron: localización, número de uñas afectadas, afectación de la matriz, tipo de onicomicosis, asociación con otras micosis y tratamiento prescrito. Resultados. En ambas muestras la proporción de pacientes psoriásicos (AP: 7,6 por ciento y DER: 3,7 por ciento) fue significativamente superior a la esperada (p < 0,001). En comparación con el resto, los pacientes psoriásicos presentaron mayor proporción de infecciones con afectación de la matriz (p < 0,05), mayor número de uñas afectadas (p < 0,05) y mayor tendencia a la localización simultánea en manos y pies. Conclusiones. A pesar de sus limitaciones, puesto que el diagnóstico de onicomicosis ha sido clínico y no por cultivo, los resultados de nuestro estudio aportan otro argumento a favor de la mayor frecuencia de onicomicosis en pacientes con psoriasis. Asimismo, los datos sugieren que en los pacientes psoriásicos la onicomicosis tiende a ser más severa.

Objective. Though classically considered rare, in recent years onychomycosis has been found to be more frequent in patients with nail psoriasis. This study aimed to assess whether patients consulting for onychomycosis present above average rates of psoriasis, and whether there are differences in the clinical presentation of onychomycosis in these patients. Design. This post hoc study was based on two epidemiological registers of patients with clinical diagnoses of onychomycosis. Setting. Primary care and dermatology units in 2004 in Barcelona. The primary care sample were 1,051 patients, and the dermatology sample, 1,906. Clinical features studied were: localization, number of nails affected, matrix involvement, type of onychomycosis, association with other types of mycosis, and treatment prescribed. Results. In both samples the proportion of patients with psoriasis (primary care: 7.6 percent and dermatology unit: 3.7 percent) were significantly above average (p < 0.001). Compared with the rest of the patients, patients with psoriasis presented a higher proportion of infection with matrix involvement (p < 0.05), a higher number of nails affected (p < 0.05) and a greater tendency towards simultaneous localization in fingers and toes. Conclusions. The diagnosis of onychomycosis was obtained clinically and not by means of culture. In spite of this limitation, the results of the study corroborate the knowledge that onychomycosis is more frequent in patients with psoriasis. The data also suggest that in patients with psoriasis the onychomycosis tends to be more severe.

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A four year study was conducted on a natural population of immature stages of Aedes aegypti after the re-invasion of Argentina by this vector in 1987. Thirty six plastic containers with 700 ml of dechlorinated water were placed in the La Plata Zoological Garden, La Plata, Argentina. A strip of filter paper around each container was added to facilitate egg counting. Eggs, larvae and pupae were counted weekly in each container from September, 1996 to August, 2000. After egg counting, papers were submerged to facilitate egg hatching and a new paper was placed in each container. Presence of A. aegypti immature stages was recorded from December-January to June during each of the four years of this study. In 1997, 13,105 eggs, 7,978 larvae and 1,476 pupae were registered with 54.7 % positive containers; during 1998, 8,194 eggs, 668 larvae and 142 pupae were recorded with 28.3 % positive containers; 13,510 eggs, 3,690 larvae and 743 pupae were registered during 1999 with 56.7 % positive containers; and 16,327 eggs, 4,669 larvae and 715 pupae during 2000 with 59.3 % of containers with presence of A. aegypti. Egg number and hatching rate were drastically reduced in 1998 when temperatures from December to May were 1 to 2.5 degrees C lower than the other years of this study. These colder than usual temperatures in the summer of 1998 were a consequence of the El Niño event.

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A survey for natural entomopathogenic fungi of the Chagas disease vector Triatoma infestans was conducted in five provinces of Argentina since 2001. Nymphs (1.5%) and adults (3.3%) infected with a strain of the fungus Beauveria bassiana were found at Dean Funes, Cordoba province, Argentina. Field collected insects that died in the laboratory were maintained in moist chambers and incubated at 22 degrees C. Beauveria bassiana from infected insects was cultured on SDAY media. Pathogenicity tests were conducted with a conidial suspension (1 x 10(7) conidia/ml) of this isolate on T. infestans adults. A mortality rate of 100% was obtained at 15 days post-infection. This is the first record of natural infection of T. infestans by B. bassiana.

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An isolate from Argentina of the fungal mosquito pathogen Leptolegnia chapmanii (ARSEF 5499), was tested against 12 species of mosquito larvae and on species of non-target aquatic invertebrates and vertebrates. The mosquito species tested were Aedes aegypti, Anopheles sp., Culex apicinus, Cx. castroi, Cx. dolosus, Cx. pipiens, Cx. renatoi, Isostomyia paranensis, Ochlerotatus albifasciatus, Oc. crinifer, Psorophora cyanescens, and P. ferox. Mosquito larvae of 10 species were susceptible, with mortality rates from 10-100%. Two mosquito species Cx. renatoi and I. paranensis were not infected by Leptolegnia. None of the non-target fauna treated was infected by L. chapmanii with exception of members of the Family Chironomidae which were susceptible at low infection rates.

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To determine the association and its magnitude between prematurity and anemia in women in their third trimester of pregnancy and at labor. An incident case-control study was conducted using 2 controls per case. Data was obtained in a tertiary hospital in Valencia, Venezuela. A total of 543 women who delivered between May and December 1996 entered into the study. Women having a preterm delivery, less than 37 weeks of gestation at delivery, were defined as cases (n = 181). Anemia was defined according to WHO as Hb less than 11 g/dL. Logistic regression was used to analyze the data and likelihood ratio test was done for model comparison. Maternal anemia was found to be significantly associated with prematurity (Odds Ratio: 1.70; 95% CI = 1.18 to 2.57 P = .001), after adjusting for Placental Abruption, PROM, Previous Premature Labor, Prenatal Care Visits, and Uterine Bleeding during more than one trimester. Maternal anemia at the end of the third trimester of pregnancy, at labor, was associated with an increased risk of prematurity.

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OBJECTIVE: To audit appropriate use of blood products in adult patients. DESIGN: A cross-sectional study with pre-set criteria. SETTING: Ciudad Hospitalaria 'Dr. Enrique Tejera', the main public tertiary-care hospital in Valencia, Venezuela. STUDY PARTICIPANTS: We studied 700 adult patients from the Medicine, Surgery, Emergency and Obstetrics departments. MAIN OUTCOME MEASURE: Appropriate use of blood products. RESULTS: Seven hundred patients who had an average of 2.45 transfusions (95% confidence interval = 2.28-2.62) were studied. Prevalence of appropriate use was 51.3% for all departments. Prevalence by department was: 72% for Medicine, 36% for Surgery, 56% for Emergency, and 47% for Obstetrics. The average number of transfusions per subject in each department was: Medicine, 3.41; Surgery, 1.75; Obstetrics, 2.09; and Emergency: 2.81 (F-test: P=0.005). Using the department of Medicine as the reference group, it was found that the departments of Surgery, Emergency and Obstetrics had a higher 'risk' of inappropriate use of transfusions, showing odds ratios of 4.4, 1.38 and 2.79 respectively. CONCLUSION: The main conclusions of this study are: (i) the prevalence of the appropriate use of blood products was 51%; (ii) packed red cells and fresh frozen plasma were the blood products with the lowest prevalence of appropriate use; and (iii) none of the departments showed rates of appropriate use of transfusions greater than 80%, implying a higher cost in health care and putting patients at a higher risk for acquiring a transfusion-transmitted disease.

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