Audiological findings in pacients treated with radiotherapy for head and neck tumors

Radiotherapy has been widely used given its increase in the successful outcomes and cure of some cancers. Aim: To evaluate the functionality of the auditory system in patients who underwent radiotherapy treatment for head and neck tumors. Materials and Methods: From May 2007 to May 2008, otorhinolaryngological and audiological evaluation (Pure Tone Audiometry (air and bone conduction), Speech Audiometry, Tympanometry, Acoustic Reflex testing and Distortion Product Otoacoustic Emissions) were performed in 19 patients diagnosed with head and neck neoplasia and treated with radiotherapy. Prospective case series study. Results: 10.5% left ears and 26.3% right ears had bilateral hearing loss soon after radiotherapy according to ASHA criteria. Conclusions: Radiotherapy treatment for head and neck cancer has ototoxic effects. Early programs of auditory rehabilitation should be offered to these patients.

A Simple and Efficient Device for Demonstrating Cross-sectional Anatomy of the Head

Described in this article is a novel device that facilitates study of the cross-sectional anatomy of the human head. In designing our device, we aimed to protect sections of the head from the destructive action of handling during anatomy laboratory while also ensuring excellent visualization of the anatomic structures. We used an electric saw to create 15-mm sections of three cadaver heads in the three traditional anatomic planes and inserted each section into a thin, perforated display box made of transparent acrylic material. The thin display boxes with head sections are kept in anatomical order in a larger transparent acrylic storage box containing formaldehyde solution, which preserves the specimens but also permits direct observation of the structures and their anatomic relationships to each other. This box-within-box design allows students to easily view sections of a head in its anatomical position as well as to examine internal structures by manipulating individual display boxes without altering the integrity of the preparations. This methodology for demonstrating cross-section anatomy allows efficient use of cadaveric material and technician time while also giving learners the best possible handling and visualization of complex anatomic structures. Our approach to teaching cross-sectional anatomy of the head can be applied to any part of human body, and the value of our device design will only increase as more complicated understandings of cross-sectional anatomy are required by advances and proliferation of imaging technology. Anat Sci Educ 3: 141-143, 2010. (C) 2010 American Association of Anatomists.

Expression and characterization of HPV-16 L1 capsid protein in Pichia pastoris

Human papillomaviruses (HPVs) are responsible for the most common human sexually transmitted viral infections. Infection with high-risk HPVs, particularly HPV16, is associated with the development of cervical cancer. The papillomavirus L1 major capsid protein, the basis of the currently marketed vaccines, self-assembles into virus-like particles (VLPs). Here, we describe the expression, purification and characterization of recombinant HPV16 L1 produced by a methylotrophic yeast. A codon-optimized HPV16 L1 gene was cloned into a non-integrative expression vector under the regulation of a methanol-inducible promoter and used to transform competent Pichia pastoris cells. Purification of L1 protein from yeast extracts was performed using heparin-sepharose chromatography, followed by a disassembly/reassembly step. VLPs could be assembled from the purified L1 protein, as demonstrated by electron microscopy. The display of conformational epitopes on the VLPs surface was confirmed by hemagglutination and hemagglutination inhibition assays and by immuno-electron microscopy. This study has implications for the development of an alternative platform for the production of a papillomavirus vaccine that could be provided by public health programs, especially in resource-poor areas, where there is a great demand for low-cost vaccines.

Identification and characterization of a new member of snake venom thrombin inhibitors from Bothrops insularis using a proteomic approach

Snake venom C-type lectin-like proteins (CLPs) are ubiquitously found in Viperidae snake venoms and differ from the C-type lectins as they display different biological activities but no carbohydrate-binding activity. Previous analysis of the transcriptome obtained from the Bothrops insularis venom gland showed the presence of two clusters homologous to bothrojaracin (BJC) chains a and P. In an effort to identify a new BJC-like molecule, we used an approach associated with proteomic technologies to identify the presence of the expressed protein and then to purify and characterize a new thrombin inhibitor from B. insularis venom. We also constructed homology models of this protein and BJC, which were compared with other C-type lectin-like family members and revealed several conserved features of this intriguing snake venom toxin family. (C)0 2007 Elsevier Ltd. All rights reserved.

Distinct tumor suppressor mechanisms evolve in rodent species that differ in size and lifespan

Large, long-lived species experience more lifetime cell divisions and hence a greater risk of spontaneous tumor formation than smaller, short-lived species. Large, long-lived species are thus expected to evolve more elaborate tumor suppressor systems. In previous work, we showed that telomerase activity coevolves with body mass, but not lifespan, in rodents: telomerase activity is repressed in the somatic tissues of large rodent species but remains active in small ones. Without telomerase activity, the telomeres of replicating cells become progressively shorter until, at some critical length, cells stop dividing. Our findings therefore suggested that repression of telomerase activity mitigates the increased risk of cancer in larger-bodied species but not necessarily longer-lived ones. These findings imply that other tumor suppressor mechanisms must mitigate increased cancer risk in long-lived species. Here, we examined the proliferation of fibroblasts from 15 rodent species with diverse body sizes and lifespans. We show that, consistent with repressed telomerase activity, fibroblasts from large rodents undergo replicative senescence accompanied by telomere shortening and overexpression of p16(Ink4a) and p21(Cip1/Waf1) cycline-dependent kinase inhibitors. Interestingly, small rodents with different lifespans show a striking difference: cells from small shorter-lived species display continuous rapid proliferation, whereas cells from small long-lived species display continuous slow proliferation. We hypothesize that cells of small long-lived rodents, lacking replicative senescence, have evolved alternative tumor-suppressor mechanisms that prevent inappropriate cell division in vivo and slow cell growth in vitro. Thus, large-bodied species and small but long-lived species have evolved distinct tumor suppressor mechanisms.

Protective efficacy of bacterial membranes containing surface-exposed BM95 antigenic peptides for the control of cattle tick infestations

The Rhipicephalus (Boophilus) microplus BM86 and BM95 glycoproteins are homologous proteins that protect cattle against tick infestations. In this study, we demonstrated that the recombinant chimeric protein comprising tick BM95 immunogenic peptides fused to the A. marginale MSP1a N-terminal region for presentation on the Escherichia coli membrane was protective against R. microplus infestations in rabbits. This system provides a novel and simple approach for the production of tick protective antigens by surface display of antigenic protein chimera on live E. coli and suggests the possibility of using recombinant bacterial membrane fractions for vaccination against cattle tick infestations. (C) 2009 Elsevier Ltd. All rights reserved.

Behavioral effects of LPS in adult, middle-aged and aged mice

Acute infections lead to alterations in behavior, collectively known as sickness behavior. which includes reduction in locomotion, food ingestion, sexual and social behavior, environmental exploration, and sleep profile. Although generally seen as undesired, sickness behavior represents a conserved strategy for animals to overcome disease. Aging process is associated with a variety of changes in immunity, which are referred to as immunosenescence, and include higher mortality by infectious diseases. Few works studied sickness behavior display in old animals. Thus, we sought to investigate the display of sickness related behaviors on aged mice. Adult(3-6 months old), middle-aged (12-15 m) and aged mice (18-22 m)were treated with i.p. LPS (200 mu g/kg) and their behaviors were assessed in the open field and in the elevated plus-maze. Exploratory activity was similar in aged mice treated or not with LPS in both apparati. In the open field, locomotion remained at baseline levels; in the elevated plus-maze, there was a time-dependent decrease in motor activity. (C) 2008 Elsevier Inc. All rights reserved