Experimental validation of a novel compact focusing scheme for future energy-frontier linear lepton colliders.

A novel scheme for the focusing of high-energy leptons in future linear colliders was proposed in 2001 [P. Raimondi and A. Seryi, Phys. Rev. Lett. 86, 3779 (2001)]. This scheme has many advantageous properties over previously studied focusing schemes, including being significantly shorter for a given energy and having a significantly better energy bandwidth. Experimental results from the ATF2 accelerator at KEK are presented that validate the operating principle of such a scheme by demonstrating the demagnification of a 1.3 GeV electron beam down to below 65 nm in height using an energy-scaled version of the compact focusing optics designed for the ILC collider.

Isotopic decay of urinary or plasma 3-methylhistidine as a potential biomarker of pathologic skeletal muscle loss.

BACKGROUND: Skeletal muscle loss accompanying aging or cancer is associated with reduced physical function and predicts morbidity and mortality. 3-Methylhistidine (3MH) has been proposed as a biomarker of myofibrillar proteolysis, which may contribute to skeletal muscle loss. METHODS: We hypothesized that the terminal portion of the isotope decay curve following an oral dose of isotopically labeled 3MH can be measured non-invasively from timed spot urine samples. We investigated the feasibility of this approach by determining isotope enrichment in spot urine samples and corresponding plasma samples and whether meat intake up to the time of dosing influences the isotope decay. RESULTS: Isotope decay constants (k) were similar in plasma and urine, regardless of diet. Post hoc comparison of hourly sampling over 10 h with three samples distributed over 10 or fewer hours suggests that three distributed samples over 5-6 h of plasma or urine sampling yield decay constants similar to those obtained over 10 h of hourly sampling. CONCLUSION: The findings from this study suggest that an index of 3MH production can be obtained from an easily administered test involving oral administration of a stable isotope tracer of 3MH followed by three plasma or urine samples collected over 5-6 h the next day.

Somatic glypican 3 (GPC3) mutations in Wilms' tumour.

Tumour and normal tissue from 41 male cases of Wilms' tumour were screened to determine the presence of sequence variants in the glypican 3 (GPC3) gene. Two non-conservative single base changes were present in tumour tissue only. These findings imply a possible role for GPC3 in Wilms' tumour development.

Genomic structure and expression profile of LPHH1, a 7TM gene variably expressed in breast cancer cell lines.

Gene identification studies, centred on a region of overlapping loss of heterozygosity in breast tumours within band 1p31.1, lead to the characterisation of LPHH1, a novel human 7TM gene. The coding sequence of LPHH1 extends over a 60 kb region and comprises in excess of 28 exons. Alternative splicing occurs minimally at five positions, four of which are within the coding sequence. The fifth region of alternative splicing occurs at the extreme 5' end of the transcript. A clear tissue specific bias in alternative exon selection is observed to some degree at all five positions, including the extreme 5' region, which raises the possibility of multiple and perhaps tissue specific promoters. One such putative promoter region, which appears to be utilised predominantly in breast cancer cells, has been identified. LPHH1 is highly evolutionarily conserved, with the simplest (19 exon) gene product being 95% identical between human and rat. Comparison of the alternatively spliced exons between three species, where data are available, has so far revealed 100% identity in the encoded peptide sequences, suggesting conservation of a functional aspect of this splicing. Gene expression has been observed in all tissues and cell lines tested, with the exception of lymphoblastoid and multiple myeloma lines, where there appears to be only a very low level of transcription. LPHH1 also appears to be downregulated in human bone marrow. These data are consistent with a role for the gene products in adhesion-mediated signalling. Analysis of a panel of breast tumour cell lines revealed that a number apparently overexpressed the gene whilst others showed very low levels of transcription. In one case, the overexpression correlated with a low level increase in gene copy number in the tumour line. In addition to differences in the overall levels of expression, LPHH1 mRNAs were alternatively spliced to varying degrees with shifts in the major gene product to truncated or altered forms in some lines. No somatic LPHH1 mutations were detected through sequence analysis of four primary breast tumours that showed loss of the adjacent 1p31.1 marker D1S207.

Photographic memory, money, and liposuction: survey of medical students' wish lists.

OBJECTIVES: To examine whether medical students made fewer altruistic wishes and more money oriented wishes in later years of the medical course than students in earlier years. DESIGN: Anonymous questionnaire survey. SETTING: Auckland University School of Medicine. PARTICIPANTS: 520 medical students from 6 years of the course responded to the questionnaire item "If you had three wishes what would you wish for?" MAIN OUTCOME MEASURES: Proportion of wishes in various categories. RESULTS: The three most popular categories of wishes were happiness (34% of students), money (32%), and altruistic wishes (31%). Rates of altruistic wishes (odds ratio=1.05, 95% confidence interval 0.94 to 1.18; P=0.36) and wishes for money (odds ratio=0.96, 0.86 to 1.08; P=0.52) did not vary over the years of the course. Female medical students were more likely than males to make altruistic wishes (36% v 26%; chi(2)=5.68, P=0. 02), intimacy wishes (25% v 18%; chi(2)=3.74, P=0.05), and happiness wishes (42% v 26%; chi(2)=18.82, P=0.0001). Men were more likely than women to make sexual wishes (5% v 0.8%; chi(2)=7.34, P=0.01). CONCLUSIONS: We found no evidence that students were less altruistic and more money oriented in the later years of the medical course.

A novel TP53 splicing mutation in a Li-Fraumeni syndrome family: a patient with Wilms' tumour is not a mutation carrier.

We report a Li-Fraumeni syndrome family in which we have detected a splice acceptor mutation in intron 3 of TP53. The mutation affects one of the invariant residues at the splice acceptor site, as a result of which two aberrant transcripts are produced. A child with Wilms' tumour aged 3 years in this family was shown not to be a mutation carrier.

Genetic and functional studies of a germline TP53 splicing mutation in a Li-Fraumeni-like family.

We report an extensive Li-Fraumeni-like family in which there is an unusual spectrum of tumours at relatively late onset. A germline TP53 splice donor mutation in exon 4 is present in all affected family members available for testing. The mutation abolishes correct splicing of intron 4 and techniques of RT-PCR have identified three different aberrant transcripts from the mutant TP53 allele. Using the yeast functional assay to analyse transcripts in cells from a number of family members with the mutant allele, TP53 appears wild-type. Functional studies have been carried out on cells from patients with and without cancer who carry the germline mutation, and on cells from unaffected individuals from the same family who do not carry the mutation. Using a number of functional endpoints known to distinguish between cells carrying mutant or wild-type TP53 alleles, we were unable to discriminate normal (wt/wt) from heterozygous (wt/mut) cells by lymphocyte apoptosis and fibroblast survival following low dose rate ionising radiation exposure. However germline mutation carriers show increased sensitivity to radiation-induced chromosome damage in the G2 phase of the cell cycle, and decreased transient and permanent G1 arrest. These studies demonstrate the importance of fully characterising the effects of TP53 germline mutations, and may explain some of the phenotypic features of this family.

Isolation and characterization of a human homologue of the latrophilin gene from a region of 1p31.1 implicated in breast cancer.

We have identified a region of chromosome 1p31.1 that shows high frequency loss of heterozygosity (LOH) in human breast cancer. This region forms part of a 7 Mb YAC/BAC contig. In order to identify candidate sequences, mutation of which might contribute to the development of disease, we have carried out mapping studies of ESTs localized to 1p31.1. This analysis, coupled with library screening and a modified 5' RACE-PCR strategy, resulted in the identification and characterization of a novel gene (LPHH1) which is located adjacent to the smallest region of overlapping loss (SRO) seen in tumours. The 4209 bp open reading frame of the 7 kb LPHH1 transcript encodes a peptide which shows approximately 65% identity to rat latrophilin, a G-coupled, seven span transmembrane protein, which binds alpha-latrotoxin. In the human sequence, whilst conservation of the transmembrane domain is high, the intra- and extracellular domains show two regions of variable structure, which are presumably generated by alternative splicing. Surprisingly, while expression of the rat gene is tightly restricted to neurological and perhaps some endocrine cells, the human sequence appears to be expressed very widely in all normal tissues tested. Northern and RT-PCR analysis of a panel of tumour cell lines showed that LPHH1 expression was variable, apparently elevated in some lines and absent or markedly reduced in others. Furthermore, characterization of the range of transcripts encoded in a breast tumour cell line, compared to normal breast, suggested that gene product variability was higher in the tumour.

G1 control gene status is frequently altered in resectable non-small cell lung cancer.

Progression through the mammalian cell cycle is controlled by a series of cyclins, cyclin-dependent kinases (cdks) and cdk inhibitors. Cyclin D1, cdk4 and the tumour suppressors p16 and retinoblastoma protein (pRb) are thought to comprise a linked system governing cell passage through the G1 phase of the cell cycle. Extending an earlier study on cyclin D1 expression, a series of resectable non-small cell lung carcinomas (NSCLCs) was examined for defects in other elements of this control system. Forty-six of fifty-one NSCLC specimens exhibited at least one alteration of these cell-cycle regulators. Immunohistochemical analysis revealed that 33% and 47% of the tumours failed to express pRb and p16, respectively. Failure to detect pRb did not correlate with loss of heterozygosity at the RB1 locus. Eleven of 12 tumours showing positive (normal) pRb staining over-expressed nuclear localised cyclin D1, including 8 with amplification of the cyclin D1 gene (CCNDI). However, in a number of lesions (n = 5) where cyclin D1 was over-expressed but localised to the cytoplasm, pRb expression was undetectable. Sequencing of exons 1 and 2 of the p16 gene (CDKN2) revealed 3/51 tumours with somatic mutations (in addition to 1 case with a germ-line alteration). All of these lesions were positive for p16 protein. No clear homozygous deletions of CDKN2 were observed by multiplex PCR. As assessed by immunostaining using a p16 monoclonal antibody, there was an inverse correlation of pRb and p16 down-regulation. Whilst patients with tumours over-expressing cyclin D1 had a significantly lower incidence of local relapse, the group whose tumours failed to express pRb had a significantly greater risk of local relapse and tended to have shortened event-free survival. Our data show that alteration of at least one cell cycle-regulator gene occurs in the majority of resectable NSCLCs.

High levels of loss at the 17p telomere suggest the close proximity of a tumour suppressor.

High levels of loss of distal markers on 17p13.3 in breast cancer suggested the presence within the region of at least one tumour-suppressor gene. Here we describe the derivation of two biallelic polymorphisms from the 17p telomeric yeast artificial chromosome (YAC) TYAC98. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and multiplex PCR analysis demonstrated that the high level of allelic imbalance observed in breast tumours represented loss of constitutional heterozygosity (LOH) and that this LOH extended to the telomere. Lung carcinoma (but not Wilms' tumour)-derived DNA again revealed a high level of loss of subtelomeric 17p sequences. Telomeric microsatellite polymorphisms from other chromosome arms did not show such elevated loss in either tumour type. This suggested that the 17p loss observed did not reflect a general telomeric instability and provided further evidence for the presence of a breast cancer tumour-suppressor gene in the distal region of 17p13.3.

A structured panel interview and group exercise in the selection of medical students.

The selection of entrants for medical school, as now widely agreed, should include measurements of non-academic as well as academic attributes. The authors have developed a process to assess the personal attributes of applicants. This included a structured panel interview carried out twice on each applicant by independent interviewers and a group exercise in which several applicants were observed whilst discussing a problem. Training for interviewers took the form of a half-day interactive workshop. One hundred and forty-one school-leaving applicants completed the new assessment. No relationship was found between academic achievement as reflected by marks in a national examination and scores in the panel interview, the group exercise, or the school principal's report. However, significant intercorrelations were found between the panel interview, group exercise and school report. The results of this experience have encouraged the Auckland School to continue to explore methods to measure these attributes in a carefully controlled study.

Genome-wide loss of maternal alleles in a nephrogenic rest and Wilms' tumour from a BWS patient.

A patient with Beckwith-Wiedemann syndrome (BWS) presented with Wilms' tumour. Examination of the nephrectomy specimen showed, in addition to the tumour, the presence of nephrogenic rests. Nephrogenic rests are thought to be precursor lesions from which a Wilms' tumour may develop. A molecular analysis examining the loss of constitutional heterozygosity (LOCH), initially for chromosome 11, was performed on peripheral blood, the normal kidney, nephrogenic rest and tumour material. The study was extended to include markers from all 23 chromosomes. At each informative, locus, LOCH of the maternal allele was shown in the nephrogenic rest and tumour material. In addition, the normal kidney displayed allele imbalance. It would appear from these results that either extensive LOCH across the genome was an early genetic event in the development of malignancy in this patient or that the tumour and rest developed from cells containing no maternal chromosomes. The apparent LOCH seen in the normal kidney sample implies that full reduction to homozygosity is consistent with a histologically normal appearance. Putative mechanisms to explain this phenomenon are discussed.

Mapping of gene loci in the Q13-Q15 region of chromosome 12.

The gene loci CDK4, GLI, CHOP and MDM2 have been mapped to the q13-q15 region of chromosome 12. Using fluorescence in situ hybridization onto simultaneously DAPI-banded metaphase chromosomes and interphase nuclei, we have more precisely mapped and ordered these loci, together with a number of Genethon microsatellite markers. GLI and CHOP localize to 12q13.3-14.1, CDK4 to 12q14 and MDM2 to 12q14.3-q15, and the gene order is cen-GLI/CHOP-CDK4-MDM2. The Genethon microsatellites D12S80 and D12S83 flank MDM2.

Determination of the gene order of the three loci CD2, NGFB, and NRAS at human chromosome band 1p13 and refinement of their localisation at the subband level by fluorescence in situ hybridisation.

The three loci NRAS, NGFB, and CD2 map to human chromosome band 1p13. Using fluorescence in situ hybridisation (FISH) to simultaneously DAPI-banded metaphase chromosomes, we have further refined the localisation of these three genes to specific subbands. NRAS localises to subband 1p13.2 and CD2 and NGFB to 1p13.1. Also, with the use of multicolour FISH, we have determined the order and orientation of the three loci in relation to the centromere. The order is cen-CD2-NGFB-NRAS.

Entry to medical school: an audit of traditional selection requirements.

The major focus in the selection of entrants for medical school has traditionally been on academic achievement in school-leaving examinations in which certain science subjects are a requirement. A longitudinal study of 413 successful applicants was undertaken to determine the relationship of these admission criteria to subsequent performance. The findings support a correlation between overall marks in the school-leaving examination and the annual Grade Point Averages. Those students in the top quartile for marks showed a significant advantage in terms of achievement but only in the preclinical years. Despite the significant correlations no predictions could be made on the basis of overall marks. No correlation was found with levels of clinical competence during the ward clerkships or with the interdisciplinary objective structured clinical examination (OSCE) in the final examination. Marks in individual school-leaving examination subjects correlated with performance during different parts of the course but only those entrants in the top quartile for marks in physics and biology showed an advantage through to the clinical years. English marks were the least correlated and failed to confer an advantage in any year of the course. None of the correlations between school-leaving marks and grades in medical school exceeded 0.4. The predictive value of school-leaving examination marks therefore accounted for only 16% of the variance in subsequent examinations. Selection of medical students on the basis of academic criteria alone is inadequate and should be accompanied by assessment of personal qualities. This School no longer uses school-leaving marks as the primary selection instrument.(ABSTRACT TRUNCATED AT 250 WORDS)

Rare variant (Glu to Lys) in the leucine zipper region of CHOP (GADD153).

CHOP (GADD153) has been shown to be a dominant negative inhibitor of specific transcription factors. Direct sequencing of the gene, amplified from the DNA of a Li-Fraumeni family index case (liposarcoma, breast cancer) revealed a constitutional variant within the coding region. This alteration, though not responsible for the Li-Fraumeni phenotype, resulted in a glutamic acid to lysine switch within the leucine zipper domain, at a residue conserved between CHOP and its potential target molecules and between the human and hamster sequences. The variant created a Taq I restriction fragment length polymorphism (RFLP) facilitating screening. Analysis of 159 breast tumour DNA samples detected two encoding variant alleles (tumour and constitutional DNA).

A transcribed polymorphism and sub-localisation of MDM2.

An NlaIV polymorphism in the 5' untranslated region of the MDM2 gene is described. MDM2 was sublocalised by fluorescence in situ hybridisation with a yeast artificial chromosome probe to 12q14.3-12q15. We demonstrate the use of the polymorphism to assess allelic imbalance in breast tumours.

Selection of Auckland medical students over 25 years: a time for change?

The selection procedures used in Auckland have been reviewed, and the characteristics of those admitted over 25 years analysed. Students are admitted either as school-leavers, mature entrants, or through an affirmative action scheme. A further small number are admitted as part of overseas development assistance. School-leavers are invited for interview on the basis of their academic achievement. Mature students and the affirmative group must have a minimum acceptable academic standard, with the interview playing a dominant role. Two thousand four hundred and forty-eight students have been admitted. The mean age was 18.6 years, and 39.7% were women. Over one half of the students had a parent who had attended university and 13% had a medical parent. One in ten students failed to complete the course, academic failure and withdrawal being of equal importance. The high loss seen in the affirmative group was due to academic failure and has led to the introduction of extra tuition and support for these students. The emphasis on academic achievement by school-leavers has excluded many applicants with outstanding personal qualities. The academic staff has therefore decided to modify the selection procedure, the final rank order of these applicants being based on their personal attributes and life experiences.