Sixth Daniel C. Baker, Jr. Memorial Lecture, Induction of cancer by DNA viruses

Cancer modelling in the NGS era - Part I: Emerging technology and initial modelling

It is today indisputable that great progresses have been made in our molecular understanding of cancer cells, but an effective implementation of such knowledge into dramatic cancer-cures is still belated and yet desperately needed. This review gives a snapshot at where we stand today in this search for cancer understanding and definitive treatments, how far we have progressed and what are the major obstacles we will have to overcome both technologically and for disease modelling. In the first part, promising 3rd/4th Generation Sequencing Technologies will be summarized (particularly IonTorrent and OxfordNanopore technologies). Cancer modelling will be then reviewed from its origin in XIX Century Germany to today's NGS applications for cancer understanding and therapeutic interventions. Developments after Molecular Biology revolution (1953) are discussed as successions of three phases. The first, PH1, labelled "Clonal Outgrowth" (from 1960s to mid 1980s) was characterized by discoveries in cytogenetics (Nowell, Rowley) and viral oncology (Dulbecco, Bishop, Varmus), which demonstrated clonality. Treatments were consequently dominated by a "cytotoxic eradication" strategy with chemotherapeutic agents. In PH2, (from the mid 1980s to our days) the description of cancer as "Gene Networks" led to targeted-gene-therapies (TGTs). TGTs are the focus of Section 3: in view of their apparent failing (Ephemeral Therapies), alternative strategies will be discussed in review part II (particularly cancer immunotherapy, CIT). Additional Pitfalls impinge on the concepts of tumour heterogeneity (inter/intra; ITH). The described pitfalls set the basis for a new phase, PH3, which is called "NGS Era" and will be also discussed with ten emerging cancer models in the Review 2nd part.

Transfer of learning across durations and ears in auditory frequency discrimination

Frequency-discrimination thresholds (FDTs) for 1-kHz tone pips with durations of 40, 100, and 200 msec were measured in the left and right ears of 10 normal-hearing listeners, before and after six 2-h frequency-discrimination training sessions involving, exclusively, the 200-msec duration and the right ear. In the trained ear, highly significant improvements in FDTs were observed at all durations. Further inspection of the data suggested complete generalization between 200 and 100 msec, but not at 40 msec. Posttraining FDTs were not found to differ between the two ears for the two untrained durations, but proved significantly smaller in the right (trained) than in the left (untrained) ear at the trained (200-msec) duration only. A control experiment involving 10 additional subjects allowed us to establish the absence of intrinsic differences in pretraining FDTs between the right and left ears. Overall, these findings indicate that frequency-discrimination learning generalizes widely across stimulus durations and across ears, but that part of the improvement is specific to the range of durations and to the ear used in training.

Evidence for two pitch encoding mechanisms using a selective auditory training paradigm

The neural mechanisms underlying the perception of pitch, a sensory attribute of paramount importance in hearing, have been a matter of debate for over a century. A question currently at the heart of the debate is whether the pitch of all harmonic complex tones can be determined by the auditory system's using a single mechanism, or whether two different neural mechanisms are involved, depending on the stimulus conditions. When the harmonics are widely spaced, as is the case at high fundamental frequencies (FOs), and/or when the frequencies of the harmonics are low, the frequency components of the sound fall in different peripheral auditory channels and are then "resolved" by the peripheral auditory system. In contrast, at low F0s, or when the harmonics are high in frequency, several harmonics interact within the passbands of the same auditory filters, being thus "unresolved" by the peripheral auditory system. The idea that more than one mechanism mediates the encoding of pitch depending on the resolvability status of the harmonics was investigated here by testing for transfer of learning in F0 discrimination between different stimulus conditions involving either resolved or unresolved harmonics after specific training in one of these conditions. The results, which show some resolvability-specificity of F0-discrimination learning, support the hypothesis that two different underlying mechanisms mediate the encoding of the F0 of resolved and unresolved harmonics.

The pathology of head and neck tumors: papillomas of the upper aerodigestive tracts, Part 18

The human papillomavirus class of DNA viruses are more than circumstantially related to oral and airway papillomas. Whether they are fully oncogenic, in the malignant sense, without other agents is questionable. Recent advances in molecular virology and the use of genus-specific (common) antigen-antibody reactions have identified papillomavirus in laryngeal and oral papillomas. Laryngeal and oral papillomas could be precancerous lesions, but they show a low-risk and long-time interval leading to malignancy unless significant iatrogenic or host variables--such as radiotherapy or immuno-incompetence--are added. Two different papillomas in the larynx can be recognized; a nonkeratinizing, papillomavirus-related lesion, and a keratinizing, usually solitary papilloma, which may or may not be related to a virus genesis and may be equated with a keratosis or clinical leukoplakia.