Abstract Renal cancer represents 3-4% of all malignancies. Its incidental detection is becoming more frequent. Surgery is the gold standard treatment for T1 renal cancer. Still, surgery is not suitable for every patient due to comorbidities or previous kidney surgery. Guidelines provided by The American Urological Association recommend thermoablation therapies as an alternative to surgery in tumors under 3 cm. Experience regarding percutaneous cryoablation in renal tumors is scarce in Latin America and there are only a handful of publications in this region regarding this subject. The objective of this study was to assess the effectiveness and security of percutaneous cryoablation in a cohort of adult patients with cT1 renal cancer (smaller than 5 cm) as an alternative to surgery. The procedures were performed with CT or Cone Beam CT guidance and under general anesthesia in sterile conditions. Cryoablation was carried out on an outpatient basis. Follow up was done with imaging studies, blood test and clinical consultation. All patients had complete response in imaging studies. There were no complications in 61% of all of them, the remaining patients suffered grade-1 complications such as hematuria, urinary reten tion and perirenal hematoma. In conclusion, percutaneous cryoablation for renal tumors is a safe and effective alternative to surgery.

Resumen El cáncer renal representa el 3 al 4% de todas las lesiones malignas y su detección incidental es cada vez más frecuente. Para los tumores renales cT1a la cirugía es el tratamiento de elección. No todos los pacientes son candidatos a este tipo de tratamiento por elevado riesgo quirúrgico debido a comorbi lidades asociadas o antecedentes de cirugía en dicho órgano. Las guías de la Asociación Americana de Urología recomiendan la termoablación como alternativa a la cirugía en tumores menores a 3 cm. La experiencia con crioablación percutánea en tumores renales es escasa en Latinoamérica y hay pocas publicaciones al respecto en esta región. El objetivo de este trabajo fue describir la efectividad y seguridad de la crioablación percutánea en una cohorte de pacientes adultos con cáncer renal cT1 (menores a 5 cm) como alternativa al tratamiento quirúrgico. Los procedimientos fueron realizados con guía de tomografía computarizada o con un angiógrafo, en condiciones estériles y bajo anestesia general. Los pacientes fueron tratados en condiciones ambulatorias. El seguimiento se realizó con estudios por imágenes, análisis de laboratorio y consulta clínica. Todos tuvieron una respuesta completa constatada por imágenes en los controles evolutivos. El 61% no tuvo complicaciones y en el resto se observaron complicaciones grado 1 como hematuria, retención urinaria y hematoma perirrenal. Se concluyó que la crioablación percutánea es segura y efectiva como alternativa a la cirugía en pacientes con tumores renales.

This work presents a study on the behavior of silane films Gamma-Aminopropyl triethoxysilane and N-(beta-aminoethyl)-gamma-Aminopropyl trimethoxysilane, obtained by dip-coating process on galvanized steel. The films were cured by thermal and ultraviolet irradiation cure processes. The substrates and zinc-based coatings are usually employed as surface treatment to improve the corrosion resistance but they employ hexavalent chromium that has a high degree of toxicity. Polymer films containing organofunctional silanes have been studied as an alternative to the passivation of zinc-based substrates. The silane coatings were evaluated by electrochemical tests and contact angle. The film morphology was characterized by scanning electron microscopy. The results showed that the films obtained presented a homogeneous coverage and that the influence of silane employed in the formulation was evident, as well as the cure parameters.

Se presenta un estudio del comportamiento de películas de silanos Gamma-Aminopropyl tirethoxysilano y del N-(Beta-Aminoethyl)-Gamma-Aminopropyl trimethoxysilano aplicados por el proceso de revestimiento por inmersión (dip-coating) sobre el acero galvanizado. Se usan los mecanismos de curado térmico y curado por irradiación ultravioleta. Los substratos y revestimientos a base de zinc reciben normalmente un tratamiento de superficie para mejorar la resistencia a la corrosión, pero usan cromo hexavalente que presenta un elevado grado de toxicidad. Las películas poliméricas conteniendo silanos organofuncionales surgen como alternativa para la pasivación de substratos a base de zinc. Los revestimientos de silano obtenidos fueron evaluados a partir de ensayos electroquímicos y ángulos de mojabilidad y la morfología fue caracterizada por microscopía electrónica de barrido. Los resultados muestran que las películas elaboradas presentan una cobertura homogénea y que el tipo de silano empleado tiene influencia en la formulación y en los parámetros de curado.

Toro Toro (T) and Yungas (Y) have been described as genetically well differentiated populations of the Lutzomyia longipalpis (Lutz & Neiva, 1912) complex in Bolivia. Here we use geometric morphometrics to compare samples from these populations and new populations (Bolivia and Nicaragua), representing distant geographical origins, qualitative morphological variation ("one-spot" or "two-spots" phenotypes), ecologically distinct traits (peridomestic and silvatic populations), and possibly different epidemiological roles (transmitting or nor transmitting Leishmania chagasi). The Nicaragua (N) (Somotillo) sample was "one-spot" phenotype and a possible peridomestic vector. The Bolivian sample of the Y was also "one-spot" phenotype and a demonstrated peridomestic vector of visceral leishmaniasis (VL). The three remaining samples were silvatic, "two-spots" phenotypes. Two of them (Uyuni and T) were collected in the highlands of Bolivian where VL never has been reported. The last one (Robore, R) came from the lowlands of Bolivia, where human cases of VL are sporadically reported. The decomposition of metric variation into size and shape by geometric morphometric techniques suggests the existence of two groups (N/Y/R, and U/T). Several arguments indicate that such subdivision of Lu. longipalpis could correspond to different evolutionary units.

Wings of a Rhodnius specimen from Alto Beni (Bolivia) was examined for identification and compared with R. stali, R. robustus, (certified Bolivian species), R. pictipes and R. prolixus (suspected Bolivian species). A projection of the unidentified wings as supplementary data into a discriminant analysis of shape revealed clear cut differences with R. stali and R. pictipes, less differences with R. prolixus, and none with R. robustus. Combining global size and shape of the wings, the unknown specimen was identified as R. robustus. Thus, this study confirmed the presence of R. robustus in Bolivia. It also highlighted the possibility of morphometrics to taxonomically interpret one individual, or even one piece of an individual, when related species data are available for comparison.

This is the first report of adult and nymphs (20 nymphs of all stages and 4 adults) of Microtriatoma trinidadensis (Lent 1951) (Hemiptera: Reduviidae: Triatominae) collected in peridomestic environment, in the department of La Paz, Bolivia. These specimens were associated to Rhodnius stali Lent, Jurberg & Galvão 1993. The exceptional finding of M. trinidadensis in peridomestic environment, illustrates the general tendency of triatominae to adapt to human dwellings and dependences.