Intraoperative radiotherapy in 1997

Codon usage bias of 1,117 Drosophila melanogaster genes, as well as fewer D. pseudoobscura and D. virilis genes, was examined from the perspective of relative abundance of isoaccepting tRNAs and their changes during development. We found that each amino acid contributes about equally and highly significantly to overall codon usage bias, with the exception of Asp which had very low contribution to overall bias. Asp was also the only amino acid that did not show a clear preference for one of its synonymous codons. Synonymous codon usage in Drosophila was consistent with "optimal" codons deduced from the isoaccepting tRNA availability. Interestingly, amino acids whose major isoaccepting tRNAs change during development did not show as strong bias as those with developmentally unchanged tRNA pools. Asp is the only amino acid for which the major isoaccepting tRNAs change between larval and adult stages. We conclude that synonymous codon usage in Drosophila is well explained by tRNA availability and is probably influenced by developmental changes in relative abundance.     

Role of intimin and bundle-forming pili in enteropathogenic Escherichia coli adhesion to pediatric intestinal tissue in vitro

Attaching and effacing (A/E) lesion formation is central to enteropathogenic Escherichia coli (EPEC) pathogenesis. In vitro experiments with human epithelial cell lines have implicated virulence plasmid-encoded bundle-forming pili (BFP) in initial binding and intimin in intimate attachment and A/E lesion formation. This study investigated the role of BFP and intimin in EPEC interactions with pediatric small intestinal biopsy tissue in in vitro organ culture. Organ culture infections (2 to 8 h) were performed with E2348/69 (a wild-type EPEC O127:H6 clinical isolate) and E2348/69 derivatives including CVD206 (eae deficient), CVD206(pCVD438) (eae-complemented CVD206), CVD206(pCVD438/01) (expressing intimin, which is nonfunctional due to a single amino acid substitution), JPN15 (spontaneous EPEC adherence factor virulence plasmid-cured E2348/69), and 31-6-1(1) (E2348/69 with a TnphoA insertion inactivation mutation in the virulence plasmid-encoded bfpA gene). Scanning and transmission electron microscopy revealed that after 8 h E2348/69 and CVD206 (pCVD438) (both Int+ BFP+) adhered to all specimens, causing A/E lesions with surrounding microvillous elongation. JPN15 and 31-6-1(1) (both Int+ BFP-) adhered and caused A/E lesions although bacteria adhered in "flat," two-dimensional groups. CVD206 and CVD206(pCVD438/01) (both Int- BFP+) did not adhere to any sample, and no pathological tissue changes were seen. Thus, in human intestinal organ culture, BFP do not appear to be involved in the initial stages of EPEC nonintimate adhesion but are implicated in the formation of complex, three-dimensional colonies via bacterium-bacterium interactions. Intimin appears to play an essential role in establishing colonization of EPEC on pediatric small intestinal tissue.     

Evaluating medication response in ADHD: cognitive, behavioral, and single-subject methodology

We introduce a novel application for linkage analysis: using bone marrow donor-recipient sib pairs to search for genes influential in graft-versus-host disease (GVHD), a major cause of morbidity and mortality following allogeneic bone marrow transplantation. In particular, we show that transplant sib pairs in which the recipient developed severe GVHD can be used to map genes in the same way as traditional discordant (affected/unaffected) sib pairs (DSPs). For a plausible GVHD model, we demonstrate that the transplant/discordant sib pair analog of the "possible triangle test" [Holmans (1993) Am J Hum Genet 52:362-374] has similar power to that of the simpler "restricted test" proposed by Risch [(1990b) Am J Hum Genet 46:229-241; (1992) Am J Hum Genet 51:673-675]. Moreover, we show that the restricted test has superior power in much of the DSP possible triangle and significantly inferior power in only a small region. Thus, we conclude that the restricted test is preferable for localizing genes with transplant/discordant sib pairs. Finally, we examine the effects of heterogeneity on the power to detect GVHD loci and demonstrate the gain in efficiency by dividing the sample into genetically more homogeneous subgroups.     

The history of sterility in Antiquity. III. The anatomy and physiology of conception in the work of Soranos of Ephesus

Soranos was highly regarded as the first and the most famous gynecologist in the antiquity. In point of fact, Soranos was not really a gynecologist but, he was the first to write a treatise about "gynecology". This work came down to us incomplete. In this study we analyse the conception's theories of Soranos.     

Trends of total reaction cross sections for heavy ion collisions in the intermediate energy range

Direct measurements of total reaction cross sections (sigma R) have been performed in the energy range of 10-300 MeV/nucleon for heavy ion collisions. A decrease of sigma R with increasing energy was observed for a wide range of masses of the colliding systems. The data suggest that sigma R reaches a minimum located around 300 MeV/nucleon independently of the projectile target combination. A dependence of sigma R on mass asymmetry of the svstem is also demonstrated. Trends of sigma R in this energy range are well reproduced by the predictions of a simple microscopic model based on individual nucleon-nucleon collisions. Our data have been employed in this framework to derive a new semi-empirical parametrization of sigma R. Most of the experimental results in the intermediate and high energy range have been reproduced by this parametrization using a single energy-dependent parameter.