Understanding MS Approaches to Peptide Characterization

Proteomics studies using mass spectrometry have become routine. The overarching goal of proteomics is to understand how the proteome changes within individuals over time, in disease states, and between individuals. Currently the field is limited by the quality of the data that can be obtained for low concentration proteins in complex biological mixtures, and by the lack of chemical knowledge that needs to be incorporated into the automated data analysis protocols that are needed to handle the massive volumes of data generated by proteomics studies. The work in this dissertation addresses both limitations. IRMPD was found to increase in efficiency with the size of a peptide, unlike CID. Attempts to quantify the increase in internal energy responsible for the increase in IRMPD efficiency with size were precluded by non-Boltzmann internal energy distributions in the population of trapped ions. FMOC derivatized peptides were found to promote sodium binding, and thereby facilitate C-terminal dissociation patterns that are easily interpreted. Infrared spectroscopy was used to measure the structure of b3 and a4 peptide fragments to gain insight into sequence and size dependent dissociation patterns. Comparison of the structures found by spectroscopy with dissociation patterns seen in CID and IRMPD gave further information about the dissociation kinetics of b3 and a4 peptide fragments.Doctor of Philosoph

Human papillomavirus cervical infection and associated risk factors in a region of Argentina with a high incidence of cervical carcinoma.

OBJECTIVE: To assess the prevalence and potential risk factors associated with human papillomavirus (HPV) cervical infection among women residing in a region of northeastern Argentina with a high incidence of cervical cancer. METHODS: A case-control study of 330 women participating in a cervical cytological screening program conducted in Posadas city, Misiones, Argentina, from February 1997 to November 1998 was carried out. Standardized questionnaires were administered, and clinical examination including colposcopy was performed. Fresh endocervical specimens for HPV DNA detection by generic polymerase chain reaction were collected and the products typed by dot-blot hybridization. RESULTS: Human papillomavirus DNA was found in 61% of samples analyzed (185/301). Samples with normal cytology had a 43% infection rate (85/199), while those classified as low-grade squamous intraepithelial lesion, high-grade squamous intraepithelial lesion, and invasive cervical carcinoma had an infection rate of 96% (53/55), 100% (29/29), and 100% (18/18), respectively. Human papillomavirus typing showed a 64% (118/185) prevalence of type 16 among all the infected population analyzed; type 16 was detected among 49% (42/85) of infected samples with normal cytology and in an average of 74% (74/100) with abnormal cytology. Sexual behavior, residence in southern Paraguay, and history of a previous sexually transmitted diseases were the main risk factors associated with high-grade cervical lesions. CONCLUSIONS: An elevated prevalence of HPV infection was detected in this population, which also has a high incidence of cervical cancer. The broad distribution of high-risk HPV type 16 in women with normal cytology and colposcopy suggests that viral infection is an important determinant of regional cancer incidence

Male breast cancer

Male breast cancer (MBC) is a rare disease representing less than 1% of all breast cancers (BC) and less than 1% of cancers in men. Age at presentation is mostly in the late 60s. MBC is recognized as an estrogen-driven disease, specifically related to hyperestrogenism. About 20% of MBC patients have family history for BC. Mutations in BRCA1 and, predominantly, BRCA2, account for approximately 10% of MBC cases. Because of its rarity, MBC is often compared with female BC (FBC). Based on age-frequency distribution, age-specific incidence rate patterns and prognostic factors profiles, MBC is considered similar to late-onset, postmenopausal estrogen/progesterone receptor positive (ER+/PR+) FBC. However, clinical and pathological characteristics of MBC do not exactly overlap FBC. Compared with FBC, MBC has been reported to occur later in life, present at a higher stage, and display lower histologic grade, with a higher proportion of ER+ and PR+ tumors. Although rare, MBC remains a substantial cause for morbidity and mortality in men, probably because of its occurrence in advanced age and delayed diagnosis. Diagnosis and treatment of MBC generally is similar to that of FBC. Men tend to be treated with mastectomy rather than breast-conserving surgery. The backbone of adjuvant therapy or palliative treatment for advanced disease is endocrine, mostly tamoxifen. Use of FBC-based therapy led to the observation that treatment outcomes for MBC are worse and that survival rates for MBC do not improve like FBC. These different outcomes may suggest a non-appropriate utilization of treatments and that different underlying pathogenetic mechanisms may exist between male and female BC

Moral structure

Chapter 12 provides a comprehensive overview of the moral structure of each of the three realms of Dante’s afterlife: Hell, Purgatory and Paradise. It examines Dante’s sources, ethical criteria, and topography, as well as his representation of moral structure in the narrative itself, and its political implications. The first section analyses the four principal regions of Hell through Virgil’s rationale: the circles of incontinence, the ‘rings’ of violence, the ‘pouches’ of simple fraud, and the pit of treacherous fraud. It then explores the three groups of souls that Virgil strikingly leaves out: the ‘neutrals’, the virtuous pagans in Limbo, and the heretics. The second section addresses four key differences between Infernal and Purgatorial suffering, explains the moral theories of disordered love and the seven capital sins underpinning the seven terraces of Dante’s Purgatory, and examines the theologically original antechamber of Purgatory, and the Earthly Paradise at the mountain’s summit. The third section highlights Dante’s distinction between what Paradise is and how it is conveyed, and shows how his layered vision of Paradise overlaps the scheme of the four cardinal and three theological virtues with the theory of astral influence on personality.Postprin

Available and emerging technologies for assessing intraoperative tissue perfusion during complex ventral hernia repair procedures

Stephen J Ferzoco Dedham Medical Associates, Dedham, MA, USA Abstract: Abdominal wall reconstructions, and complex ventral hernia repairs in particular, pose significant challenges to surgeons and are associated with serious postoperative wound healing complications often related to poor tissue perfusion. Maintenance of adequate perfusion of central adipocutaneous tissue is critical for minimizing risk of wound-related complications following herniorrhaphy; however, accurate tissue perfusion assessment can be challenging in this setting. Technologies such as thermography and laser Doppler flowmetry are not widely used in clinical settings to assess tissue perfusion, and most surgeons currently rely upon subjective assessments of tissue viability to guide intraoperative decisions regarding reconstruction. New technological developments, including spectroscopic imaging and indocyanine green-based near-infrared laser fluorescence, permit quantitative, real-time, intraoperative visualization of tissue perfusion and have demonstrated sensitivity and accuracy in a variety of reconstructive settings. Evidence suggests these technologies can be used to optimize perfusion at the time of operation and prevent perfusion-related complications such as flap necrosis. Future studies and physician reports describing these perfusion assessment technologies in complex ventral hernia repair will supply important information regarding their utility in patients undergoing this procedure. Keywords: indocyanine green imaging, spectroscopic imaging, hernia repair, intraoperative tissue perfusion, complications, tissue ischemi

25. Changes

Over the centuries, much scholarship on Dante’s Commedia has taken the form of the lectura Dantis, in which one digs as deeply as one can into the depths of the poem’s text. The project of Cambridge’s vertical readings, on the other hand, is reminiscent not of the deep shafts dug by miners but rather of long narrow trenches, of the sort gently excavated by archaeologists. The trenches we are digging in our enterprise follow not a physical structure but a numerical one. Someone like Dante, who..

A Role for Glycosylphosphatidylinositol Anchored Proteins in T Lymphocyte Homeostasis

The glycosylphosphatidylinositol (GPI) anchorage of proteins to the outer leaflet of the plasma membrane imparts unique properties and controversial functionality. While all GPI-anchored proteins (GPI-AP) contain a conserved GPI core structure, they represent a large class of functionally diverse proteins with known capacities for intracellular signalling, protein trafficking, and localization within membrane microdomains, termed lipid rafts (LR). Many studies have implicated GPI-AP as regulators of T cell receptor (TCR)-mediated cellular activation, however, as they are not transmembrane molecules, mechanisms underpinning their signalling capacity remain elusive. We have isolated a mutant clonal variant devoid of GPI-AP. This T cell clone produced 10-100-fold more TCR-induced interleukin (IL)-2 than the GPI-AP+ parent clone. As GPI-AP reside exclusively within LR, we hypothesized that within this signalling scaffold, they may function as essential regulators of TCR/CD3-mediated “on” and “off” signals. Model systems utilizing GPI-AP+ and GPI-AP- variants of the antigen specific, IL-2-dependent T cell clone, and primary GPI-AP- T cells were generated towards directly testing this hypothesis. In the clonal system, GPI-AP deficiency was shown to impart a prolonged TCR/CD3-induced clonal expansion, which correlated with both enhanced IL-2 messenger RNA (mRNA) and protein production. The re-expression of GPI-AP abrogated the prolonged growth/survival phenotype, consistent with a GPI-AP-dependent attenuation of TCR/CD3 signalling. The phenotype was recapitulated in primary GPI-AP- CD4+ T cells. Hypersensitive TCR/CD3 signalling in the primary model correlated with an enhanced basal kinase activity of the Src-family protein tyrosine kinase Fyn, essential for TCR/CD3 induced IL-2 production. The role of the GPI-anchor, as opposed to that of one or more GPI-anchored proteins in supporting this phenotype was assessed using GPI-anchor sufficient, GPI-AP deficient primary T cells. Preliminary results demonstrated that the TCR/CD3-induced IL-2 phenotype of GPI+/GPI-AP- closely resembles that of GPI-AP+, wild-type T cells. While a mixed genetic background in these GPI+/GPI-AP- T cells precludes formal proof of this conclusion, results thus far attribute a potentially novel role for GPI in regulating homeostatic T cell physiology. The biological significance of the results may provide insight into the mechanism underpinning the human disease paroxysmal nocturnal hemoglobinuria, the maintenance of cellular homeostasis and proliferative disease states writ large.Ph.D