Biliary Tract Cancer: Molecular Biology of Precursor Lesions.

Biliary tract cancer is a devastating malignancy of the bile ducts and gallbladder with a dismal prognosis. The study of precancerous lesions has received considerable attention and led to a histopathological classification which, in some respects, remains an evolving field. Consequently, increasing efforts have been devoted to characterizing the molecular pathogenesis of the precursor lesions, with the aim of better understanding the mechanisms of tumor progression, and with the ultimate goal of meeting the challenges of early diagnosis and treatment. This review delves into the molecular mechanisms that initiate and promote the development of precursor lesions of intra- and extrahepatic cholangiocarcinoma and of gallbladder carcinoma. It addresses the genomic, epigenomic, and transcriptomic landscape of these precursors and provides an overview of animal and organoid models used to study them. In conclusion, this review summarizes the known molecular features of precancerous lesions in biliary tract cancer and highlights our fragmentary knowledge of the molecular pathogenesis of tumor initiation.

Microbiology of the middle ear fluid in Costa Rican children between 2002 and 2007.

BACKGROUND: Because the microbiology and susceptibility patterns of middle ear fluid pathogens in children with otitis media change over time, an active surveillance is recommended to establish appropriate therapeutic guidelines. OBJECTIVE: To analyze the microbiology and susceptibility pattern of middle ear pathogens obtained from Costa Rican children with acute otitis media (AOM), recurrent otitis media (ROM) and therapeutic failure otitis media (OMTF) between 2002 and 2007. PATIENTS AND METHODS: 1108 children aged 2-92 months who participated in various otitis media clinical trials between the years 2002 and 2007. RESULTS: Among the study population, 880 were children with AOM (61% <24 months of age), 138 were children with ROM (54% <24 months of age) and 90 were children with OMTF (67% <24 months of age). Bilateral otitis media was more frequent in children with OMTF (44%) than in children with AOM (37%) (P=0.19) and ROM (27%) (P=0.009). Presence of siblings <8 years of age was more frequently observed in children with OMTF (73%) than in children with ROM (65%) (P=0.0001) and AOM (47%) (P=0.000002). Overall Streptococcus pneumoniae (44%) was the most common pathogen isolated followed by Haemophilus influenzae (37%), Moraxella catarrhalis (11%) and Streptococcus pyogenes (4%). S. pneumoniae was the most common pathogen in AOM (44%) and ROM (47%), however, H. influenzae was the most common pathogen in OMTF (40%). Among all H. influenzae, an increase in the number of ß-lactamase producing strains was observed from 5.2% in 2001 to 14% (P=0.04) in 2007 and this was associated with an increase in the use of amoxicillin. An increase in the number of M. catarrhalis was also observed, from 3% (9/350) in 2001 to 11% (71/628) (P=0.000003) in 2007. During the study period the incidence of penicillin non-susceptible S. pneumoniae was 42/211 (20%) in children with AOM; 5/35 (17%) in children with ROM and 5/17 (42%) in children with OMTF. M. catarrhalis cases increased from 8% in 2004 to 17% in 2007 (P=0.0005) and S. pyogenes decreased from 7% in 2002-2004 to 1% in 2005-2007 (P=0.001). CONCLUSIONS: In Costa Rica, S. pneumoniae remains the most common pathogen in children with AOM and ROM whereas non-typable H. influenzae remains the most common pathogen in children with OMTF. A significant increase in the number of ß-lactamase positive H. influenzae and M. catarrhalis has been observed in recent years.

Valores hematológicos de psitácidos de los géneros ara y amazona cautivos en zoológicos de Venezuela / Hematological values in psittacine birds, ara and amazona genus, captive in Venezuela zoological parks

Se obtuvieron muestras sanguíneas de 104 aves cautivas en zoológicos de Venezuela con la finalidad de obtener valores hematológicos de referencia en especies de los géneros Amazona (loros) y Ara (guacamayas). Utilizando métodos hematológicos manuales se determinaron los parámetros: Conteo de Glóbulos Rojos (CGR), Conteo de Glóbulos Blancos (CGB), Hematocrito (Hcto), Volumen Corpuscular Medio (VCM), y Conteo diferencial de Leucocitos. Se calcularon los valores absolutos leucocitarios. Los valores promedios de los parámetros hematológicos en el grupo Ara y Amazona, respectivamente fueron CGR (3,02x106µL y 2,33x106µL), Hcto (49,6 por ciento y 50,03 por ciento), VCM (175,5 fL y 225,5 fL), CGB (11,804 cel/ µL y 9,752 cel/µL). Las medias del conteo diferencial de leucocitos fueron: Heterófilos (67,2 por ciento y 62,5 por ciento), Linfocitos (28,2 por ciento y 31,6 por ciento), Eosinófilos (1,6 por ciento y 2,9 por ciento), Monocitos (1,4 por ciento y 1,9 por ciento). Estos resultados coinciden con los intervalos de referencia reportados en la literatura para otros países, a excepción del conteo de Eosinófilos, el cual se encontró aumentado posiblemente debido a parasitosis intestinales mantenidas por la condición de cautividad.

In order to determine hematological reference values, a total of 104 blood samples were obtained from captive birds of Ara and Amazona genera in different Venezuelan zoos. Red Blood Cell (RBC), Packed Cell Volume (PCV), Mean Corpuscular Volume (MCV), White Blood Cell (WBC) and leukocytes differential counts were measured using manual haematological methods. Absolute leukocytes values were calculated hematological parameters of Ara and Amazona genus respectively were RBC (3.02x106µL and 2.33 x106µL), PCV (49.6 and 50.03%), MCV (175.5 fL and 225.5 fL ), WBC (11804 cel x µL and 9752 c/uL) Heterophils (67.2 and 62.5%) , Band Heterophils (0.9 and 0.9%) Lymphocytes (28.2 and 31.6%), Eosinophils (2.9 and 1.6%), Monocytes (1.97 and 1.4%). These results coincide with the reference intervals documented in other countries for this genera. Only Eosinophils values were higher than reported values probably due to intestinal parasitic diseases during captivity.