A Human Minor Histocompatibility Antigen Resulting from Differential Expression due to a Gene Deletion

Minor histocompatibility antigens (minor H antigens) are targets of graft-versus-host disease and graft-versus-leukemia responses after allogeneic human leukocyte antigen identical hematopoietic stem cell transplantation. Only a few human minor H antigens have been molecularly characterized and in all cases, amino acid differences between homologous donor and recipient proteins due to nucleotide polymorphisms in the respective genes were responsible for immunogenicity. Here, we have used cDNA expression cloning to identify a novel human minor H antigen encoded by UGT2B17, an autosomal gene in the multigene UDP-glycosyltransferase 2 family that is selectively expressed in liver, intestine, and antigen-presenting cells. In contrast to previously defined human minor H antigens, UGT2B17 is immunogenic because of differential expression of the protein in donor and recipient cells as a consequence of a homozygous gene deletion in the donor. Deletion of individual members of large gene families is a common form of genetic variation in the population and our results provide the first evidence that differential protein expression as a consequence of gene deletion is a mechanism for generating minor H antigens in humans

WHO criteria for measles elimination: A critique with reference to criteria for polio elimination

Smallpox was formally declared as eradicated in 1979. Smallpox is the only infectious disease of humans that has ever been eradicated. Poliomyelitis has been eliminated from three of the six World Health Organization (WHO) regions although not all countries within those regions always meet the elimination criteria. Elimination criteria for measles are being discussed. We use poliomyelitis and measles as examples to illustrate our assertion that the current approach to documenting measles elimination relies too heavily on criteria for surveillance quality, disadvantaging countries with long established and relatively inflexible surveillance systems. We propose an alternative approach to documenting measles elimination, with the two key criteria being molecular evidence to confirm the lack of a circulating endemic genotype for at least one year and maintenance of 95% coverage of one dose of measles-containing vaccine, with an opportunity for a second dose. Elimination status should be reviewed annually. We suggest four principles that should guide development of final criteria to document measles elimination: countries that have eliminated measles should be able to meet the elimination criteria; quality surveillance criteria are necessary but not sufficient to define elimination; quality surveillance criteria should be guided by elimination criteria, not the other way around; and elimination criteria should not differ between the WHO regions without good reason

Demographic, behavioural and anthropometric correlates of food liking: A cross‐sectional analysis of young adults

The degree to which foods are liked or disliked is associated with dietary intake and health behaviours. However, most food liking research has focused on single foods and nutrients and few studies have examined associations with demographics and health behaviours. Thus, this study aimed to investigate the association between food liking and socio‐demographics, health behaviours, diet quality and body mass index (BMI) in a sample of young Australian adults. Data from 1728 undergraduate students (21.8 (standard deviation [SD] 6.0) years; 76% female) were used. Food liking scores and a diet quality index (Dietary Guideline Index, DGI) were estimated from a Food Liking Questionnaire and Food Frequency Questionnaire (FFQ), respectively. Multivariate linear regression analyses were used to assess the association between food liking and correlates. Young adults with higher liking for encouraged core foods were older, female, did their own food shopping, consumed less packaged foods and had better diet quality. Higher liking for discretionary foods and beverages was associated with less healthy behaviours, such as smoking, higher BMI and lower diet quality. These results suggest that food liking measures may offer an appropriate methodology for understanding influences on young adults’ food choices, adding to the body of literature investigating the potential for food liking scores to assess diet–disease relationships

An uncertain future, deep uncertainty, scenarios, robustness and adaptation: How do they fit together?

A highly uncertain future due to changes in climate, technology and socio-economics has led to the realisation that identification of “best-guess” future conditions might no longer be appropriate. Instead, multiple plausible futures need to be considered, which requires (i) uncertainties to be described with the aid of scenarios that represent coherent future pathways based on different sets of assumptions, (ii) system performance to be represented by metrics that measure insensitivity (i.e. robustness) to changes in future conditions, and (iii) adaptive strategies to be considered alongside their more commonly used static counterparts. However, while these factors have been considered in isolation previously, there has been a lack of discussion of the way they are connected. In order to address this shortcoming, this paper presents a multidisciplinary perspective on how the above factors fit together to facilitate the devel- opment of strategies that are best suited to dealing with a deeply uncertain future

Scaling at the OTOC Wavefront: Integrable versus chaotic models

Out of time ordered correlators (OTOCs) are useful tools for investigating foundational questions such as thermalization in closed quantum systems because they can potentially distinguish between integrable and nonintegrable dynamics. Here we discuss the properties of wavefronts of OTOCs by focusing on the region around the main wavefront at $x=v_{B}t$, where $v_{B}$ is the butterfly velocity. Using a Heisenberg spin model as an example, we find that a propagating Gaussian with the argument $-m(x)\left( x-v_B t \right)^2 +b(x)t$ gives an excellent fit for both the integrable case and the chaotic case. However, the scaling in these two regimes is very different: in the integrable case the coefficients $m(x)$ and $b(x)$ have an inverse power law dependence on $x$ whereas in the chaotic case they decay exponentially. In fact, the wavefront in the integrable case is a rainbow caustic and catastrophe theory can be invoked to assert that power law scaling holds rigorously in that case. Thus, we conjecture that exponential scaling of the OTOC wavefront is a robust signature of a nonintegrable dynamics.Comment: 8 pages, 2 figure

Semiclassical Treatment of Diffraction in Billiard Systems with a Flux Line

In billiard systems with a flux line semiclassical approximations for the density of states contain contributions from periodic orbits as well as from diffractive orbits that are scattered on the flux line. We derive a semiclassical approximation for diffractive orbits that are scattered once on a flux line. This approximation is uniformly valid for all scattering angles. The diffractive contributions are necessary in order that semiclassical approximations are continuous if the position of the flux line is changed.Comment: LaTeX, 17 pages, 4 figure

Studies of non auto-transferring plasmids in Escherichia coli and salmonellae

A number of non auto-transferring plasmids (NTP) coding for drug resistance or for colicin synthesis were examined in Escherichia coli and salmonellae. These plasmids form Class 2 transfer systems in which the resistance or colicin determinant(s) and the transfer factor are discrete plasmids, independent of each other in the host cell. The transfer frequency of the determinant depends on the type of transfer factor used for its mobilisation. For example, the streptomycin-sulphonamide resistance (SSu) determinant was transferred more efficiently by I-like transfer factors than by F-like plasmids. The plasmids NTP1 to NTP11, of which eight coded for drug resistance and three for colicinogeny, fell into at least six compatibility groups. A number of wild SSu-resistant strains of salmonellae and E.coli carried non-transferring determinants incompatible with the ampicillin-sulphonamide resistance (ASu) determinant. These SSu plasmids are probably phylogenetically related to the prototype SSu determinant from which ASu was derived. NTP1 to NTP11 consist of covalently closed circular DNA molecules with mean contour lengths between 2.22 and 4.53 mm. All are present in multiple copies per chromosome in E.coli K12. A non-transferring kanamycin resistance determinant K reversed the "fertility inhibition +" (fi +) property of Salmonella typhimurium phage type 36, to make it fi -. K had a similar effect on at least fourteen other strains of S. typhimurium. Examination of five fi+ S. typhimurium strains and one fi- strain demonstrated that the fi+ property was dependent on the presence of a plasmid, which was designated MP10. Molecular studies confirmed that K was incompatible with MP10 and the two plasmids showed a high degree of DNA homology. K was probably formed by recombination between a kanamycin resistance determinant and the MP10 plasmid of the original S. typhimurium host. The K plasmid is present as approximately one copy per chromosome and it has a mean contour length of 18.1 mm. These results establish that there are at least two sorts of non auto-transferring plasmids. Plasmids of the first type are small, less than 5 pm in length, and exist in multiple copies per chromosome. In contrast, members of the second type are usually much larger in size and are present as approximately one copy per chromosome. This thesis is a report of research performed by the author in the Enteric Reference Laboratory, Central Public Health Laboratory, Colindale, and in the School of Pharmacy, University of London from 1970 to 1975. Accounts of parts of this work have been published as follows: Anderson, E. S. and Smith, H. R. (1972). Fertility inhibition in strains of Salmonella typhimurium. Molec. Gen. Genet., 118, 79-84. Smith, H. R., Grindley, J. N., Grindley, N. D. F. and Anderson, E. S. (1970). Depression of F-lac in Salmonella typhimurium by a determinant for kanamycin resistance. Genet. Res. Camb., 16, 349-353. Smith, H. R., Humphreys, G. 0., Grindley, N. D. F., Grindley, J. N. and Anderson, E. S. (1973). Molecular studies of an fi+ plasmid from strains of Salmonella typhimurium. Molec. Gen. G.net., 126, 143-151. Smith, H. R., Humphreys, G. 0. and Anderson, E. S. (1974). Genetic and molecular characterisation of some non-transferring plasmids. Molec. Gen. Genet., 129, 229-242

Bostonia. Volume 15

Founded in 1900, Bostonia magazine is Boston University's main alumni publication, which covers alumni and student life, as well as university activities, events, and programs

Billiard Systems in Three Dimensions: The Boundary Integral Equation and the Trace Formula

We derive semiclassical contributions of periodic orbits from a boundary integral equation for three-dimensional billiard systems. We use an iterative method that keeps track of the composition of the stability matrix and the Maslov index as an orbit is traversed. Results are given for isolated periodic orbits and rotationally invariant families of periodic orbits in axially symmetric billiard systems. A practical method for determining the stability matrix and the Maslov index is described.Comment: LaTeX, 19 page