Introduction Biliary papillomatosis is a disease characterized by multiple papillary tumours of variable distribution and extent in the intrahepatic and/or extrahepatic biliary tree 1-5. Papillary carcinoma can develop within these lesions. Because biliary papillomatosis is a rare biliary pathological entity, its clinical features and outcome are not well known 5. Recently we experienced a case...

In this paper we extend the concept of ∆-confluence to ∆k-confluence by allowing more generalized junctions, called ∆k-junctions. We present an algorithm for recognizing graphs that are ∆k-confluent. We then generalize ∆k-confluence to Ok-confluence by allowing non-intersecting chords within a junction, resulting in Ok-junctions. We present an algorithm for recognizing graphs that are Ok-conflu...

OBJECTIVE The objective of this study was to determine whether human papillomavirus (HPV) infections are involved in the development of papillomatosis lesions of the lower female genital tract. METHODS A total of 616 biopsy specimens of genital papillomatous lesions (307 nodular and 309 papular types) from 598 patients were anaylyzed for the presence of HPV DNA sequences by polymerase chain r...

Reticulate, or non-bifurcating, evolution is now recognized as an important phenomenon shaping the histories of many organisms. It appears to be particularly common in plants, especially in ferns, which have relatively few barriers to intra- and interspecific hybridization. Reticulate evolutionary patterns have been recognized in many fern groups, though very few have been studied rigorously us...

The seed exomorphic characteristics of four taxa (Cardamine graeca, C. impatiens subsp. impatiens, raphanifolia and uliginosa) belonging to Cardamine were investigated with scanning electron microscopy (SEM). This study presents characteristics, including colour, shape, winged, measures, coat pattern. Four patterns observed; regularly reticulate, irregularly-reticulate, blister tuberculate-reti...

The tree structure is currently the accepted paradigm to represent evolutionary relationships between organisms, species or other taxa. However, horizontal, or reticulate, genomic exchanges are pervasive in nature and confound characterization of phylogenetic trees. Drawing from algebraic topology, we present a unique evolutionary framework that comprehensively captures both clonal and reticula...