The global burden of melanoma: results from the Global Burden of Disease Study 2015.

BACKGROUND: Despite recent improvements in prevention, diagnosis and treatment, vast differences in melanoma burden still exist between populations. Comparative data can highlight these differences and lead to focused efforts to reduce the burden of melanoma. OBJECTIVES: To assess global, regional and national melanoma incidence, mortality and disability-adjusted life year (DALY) estimates from the Global Burden of Disease Study 2015. METHODS: Vital registration system and cancer registry data were used for melanoma mortality modelling. Incidence and prevalence were estimated using separately modelled mortality-to-incidence ratios. Total prevalence was divided into four disease phases and multiplied by disability weights to generate years lived with disability (YLDs). Deaths in each age group were multiplied by the reference life expectancy to generate years of life lost (YLLs). YLDs and YLLs were added to estimate DALYs. RESULTS: The five world regions with the greatest melanoma incidence, DALY and mortality rates were Australasia, North America, Eastern Europe, Western Europe and Central Europe. With the exception of regions in sub-Saharan Africa, DALY and mortality rates were greater in men than in women. DALY rate by age was highest in those aged 75-79 years, 70-74 years and ≥ 80 years. CONCLUSIONS: The greatest burden from melanoma falls on Australasian, North American, European, elderly and male populations, which is consistent with previous investigations. These substantial disparities in melanoma burden worldwide highlight the need for aggressive prevention efforts. The Global Burden of Disease Study results can help shape melanoma research and public policy.

The central role played by peptides in the immune response and the design of peptide-based vaccines against infectious diseases and cancer.

Vaccines are one of the most cost effective methods of improving public health thereby increasing the quality of life. Prophylactic and therapeutic treatment by vaccines can prevent infectious diseases and some cancers and could also be used in the treatment of autoimmune disorders. An appreciation of this potential has resulted in a burgeoning literature which not only describes the scientific efforts being made into designing new and improved vaccines but also drives the efforts being made by public health organizations world-wide in delivering vaccines to the community. At the forefront of technologies being applied to the design of vaccines is the use of synthetic peptides; the chemical technologies used to assemble peptides have made great strides over the last decade and assembly of hi-fidelity peptides which can be of high molecular weight, multimeric or even branched is now almost routine. Together with the advances in peptide technology our understanding of the molecular events that are necessary to induce immune responses has also made great strides. The central role that peptides play in immune recognition is now recognised and rules are emerging that are being applied to the construction of peptide-based vaccines that, in the right context, can induce humoral (antibody) and cellular (cytotoxic and helper T cell) immune responses. Synthetic peptides are exquisitely placed to answer questions about immune recognition and along the way to provide us with new and improved vaccines.

[Survival, mortality and quality of life after pylorus-preserving or classical Whipple operation. A systematic review with meta-analysis]. / Uberleben, Mortalität und Lebensqualität nach pyloruserhaltender oder klassischer Whipple-Operation. Systematische Ubersichtsarbeit mit Metaanalyse.

BACKGROUND: Two surgical procedures are mainly performed for the treatment of pancreatic head cancer and periampullary carcinoma: the classical Whipple operation and the pylorus-preserving Whipple operation. METHODS: This manuscript represents an extension of a systematic review and meta-analysis previously published in the Annals of Surgery. A systematic literature search was performed in MEDLINE, EMBASE and the Cochrane Library (central) to identify randomized controlled trials (RCTs) and observational studies. A meta-analysis based on a random-effects model was performed for the hazard ratios (HR) of survival and the odds ratios (OR) of postoperative mortality. The results of the different studies on quality of life (QoL) could not be summarized quantitatively in a meta-analysis and were therefore summarized qualitatively. Subgroup analyses were performed by study type, RCTs, prospective cohort studies (PSs), retrospective cohort studies (RSs), study quality and tumor localization (pancreatic head cancer versus periampullary carcinoma). RESULTS: The systematic literature search retrieved 4,503 studies of which 4,460 did not fulfill the inclusion criteria. The remaining 43 studies (6 RCTs, 12 PSs and 25 RSs) representing 3,893 patients were finally included in the review. There was neither a significant survival difference for patients with pancreatic head cancer in the pooled estimate of the RCTs (HR 0.80; 95% CI 0.53-1.22; p=0.16) nor in the pooled estimate of the PSs (HR 0.84; 95% CI 0.7-1.0; p=0.95) or the RSs (HR 0.84; 95% CI 0.7-1.01; p=0.21). Survival of patients with periampullary carcinoma was not significantly different in the RCTs (HR 1.02; 95% CI 0.49-2.13; p=0.3), the PSs (HR 1.26; 95% CI 0.46-3.42; p=0.65) or the RSs (HR 0.86; 95% CI 0.6-1.24; p=0.33). Postoperative mortality was not significantly different after both types of operations (RCTs: HR 0.49; 95% CI 0.17-1.4; p=0.18; PSs: HR 0.63; 95% CI 0.34-1.18; p=0.15; RSs: HR 0.7; 95% CI 0.37-1.31; p=0.27). QoL was reported as either the same in both groups or in favor of the pylorus-preserving Whipple operation. CONCLUSIONS: Mortality, survival and QoL were not significantly different between the classical Whipple and the pylorus-preserving Whipple operations. Given the poor quality of the underlying trials a pragmatic RCT is recommended to prove the findings of this systematic review.

Antigenic and immunogenic properties of synthetic peptide-based T-cell determinant polymers.

Presentation of T-cell determinants to the immune system in multimeric form has clear advantages and the production of synthetic peptide-based polymers using the solubilisable KS resin described by Goddard et al. [1] provides a method of assembling such polymers and also offers the means for making heteropolymers. The present study investigates the potential of polymeric synthetic peptide constructs in eliciting proliferative T-cell responses to determinants of the influenza virus hemagglutinin. The induction of vigorous CD4+ T-cell immunity was achieved with a polymeric construct containing two different T-cell determinants. The data presented here also highlight the fact that distancing the determinant from the support backbone with appropriate amino acid residues is an important consideration for the success of these polymeric immunogens. This approach may be readily applied in other systems where induction of helper T-cell responses are required.

The assembly and immunological properties of non-linear synthetic immunogens containing T-cell and B-cell determinants.

For the rational design of synthetic vaccines, a potential immunogen must contain the appropriate helper T-cell and B-cell determinants to elicit a strong and relevant immune response. In this study we describe a method for the assembly of antigenic determinants from influenza virus hemagglutinin onto a lysine-based support, resulting in dimeric and trimeric constructs bearing both T-cell and B-cell determinants. A panel of synthetic immunogens was constructed incorporating peptides representing: (i) the B-cell determinant TLKLATG and the T-cell determinant PKYVKQNTLKLA which overlaps this sequence in the heavy chain (HA1) of the hemagglutinin; and (ii) the same B-cell determinant with an alternate T-cell determinant ALNNRFQIKGVELKS from the light chain (HA2). With these peptides we were able to investigate the effects of altering the source of T-cell help, increasing the copy number of B-cell determinants as well as comparing the presentation of determinants in either linear tandem or branched geometries. In general, peptides incorporating the non-native helper T-cell determinant in a branched conformation were superior immunogens, eliciting higher titres of both peptide-specific and virus-specific antibody. Increasing the copy number of the B-cell determinant also proved to be an advantage in terms of increasing antibody titres. Other evidence was obtained indicating that presentation of determinants to T cells may be different for linear peptide constructs compared to branched immunogens bearing the same determinants.

The geometry of synthetic peptide-based immunogens affects the efficiency of T cell stimulation by professional antigen-presenting cells.

In the pathway leading to antibody production there are two points at which CD4(+) T(h) cells need to be recruited. The first of these is priming of T cells by their interaction with dendritic cells (DC) bearing antigen presented on MHC class II molecules and the second is the collaborative interaction of these primed T cells with B cells presenting the same antigen. We have previously shown that the configuration of T and B cell determinants within synthetic peptide immunogens can greatly influence the amount of immunogen required to produce an antibody response. Here we investigate whether the difference in potency of different immunogens is related to their ability to be presented by either DC or B cells. We show that determinants in a branched configuration, which are the most efficient at eliciting antibody in vivo, are presented to T cell clones by splenic CD8(-) DC 10-fold more efficiently than the corresponding determinants in a tandem linear arrangement. B cells also showed preferential presentation of branched immunogens to one T cell clone but in contrast to DC, not to a second T cell clone, indicating differences between the two antigen-presenting cell types. We also show that branched immunogens have a greater stability in serum compared to linear peptides, which may further enhance the differences in their in vivo potency.

Preparation and properties of totally synthetic immunogens.

Although the induction of antibodies and T cells by synthetic peptides representing defined antigenic determinants is a routine laboratory procedure, their use as vaccines has not yet been generally realised. There are a number of reasons for this and paramount is the limitation of valency which affects not only immunogenicity, but also the coverage of the antigenic universe. This paper is a review of our own work in which we have assembled synthetic peptides into multivalent artificial proteins and then examined their immunological properties.

Differential effect of CD8(+) and CD8(-) dendritic cells in the stimulation of secondary CD4(+) T cells.

Dendritic cells (DC), in their role in initiation of the adaptive immune response, have been extensively studied for their capacity to interact and stimulate naive T cells. Subsets of mature murine DC isolated directly from the spleen have been shown to differ in their ability to induce proliferative responses in both primary CD4(+) and primary CD8(+) T cells; the myeloid-related CD8alpha(-) DC induce a more intense or prolonged proliferation of naive T cells than do the lymphoid-related DC bearing CD8alpha despite similar expression of MHC and co-stimulatory molecules. Here we examine the interaction of these DC subpopulations with T cells already in the activated or memory state which are known to have greater sensitivity to antigen stimulation and bear receptors with increased capacity for signal transduction. We show that influenza virus-specific CD4(+) T cell clones and splenic T cells from peptide-primed animals proliferated in response to antigen presented by separated splenic CD8(-) DC. In contrast, these T cells showed only weak, if any, proliferation in response to CD8(+) DC despite observable cluster formation in the cultures. The differential between the two DC types in inducing proliferation was even more pronounced than previously seen with primary T cells and did not reflect differential longevity of the DC in culture, altered response kinetics or deviation from IL-2 to IL-4 induction with CD8(+) DC, but was related to the levels of IL-2 induced. The deficiency in the CD8(+) DC was not overcome by using infectious virus rather than synthetic peptide as the antigen source. These results show that lymphoid-related CD8(+) splenic DC, despite their mature phenotype, fail to provide appropriate signals to secondary CD4(+) T cells to sustain their proliferation.