Genome screening using extremely discordant and extremely concordant sib pairs

We applied extreme sib-pair methods in two ways to the GAW10 Problem 2A data sets to detect susceptible quantitative trait loci using extremely discordant sib pairs only, and combining them with the available extremely concordant sib pairs as suggested by the authors elsewhere. Ten successive original replicates were combined into one sampling pool so as to get the necessary number of extreme sib pairs. A total of 100 replicates were used to produce 10 such data sets for both initial detection and confirmations. Strong signals were found with markers D5G15 for Q1, D8G27-28 for Q4, and D9G7-9 for Q5.     

Subacute cutaneous lupus erythematosus induced by radiation therapy

The authors describe for the first time a case of splenic infarction in a 7-year-old boy with portal hypertension and biliary cirrhosis secondary to biliary atresia. This rare complication may cause serious acceleration of chronic liver failure.     

Microplate-array diagonal-gel electrophoresis (MADGE) and melt-MADGE: tools for molecular-genetic epidemiology

Microplate-array diagonal-gel electrophoresis (MADGE) was invented for molecular-genetic epidemiological studies. It combines direct compatibility with microplates, convenient polyacrylamide-gel electrophoresis and economy of time and reagents at minimal capital cost, and enables one user to run up to several-thousand gel lanes per day for the direct assay of single-base variations. Melt-MADGE adds temporal-thermal-ramp apparatus to achieve similar throughput for de novo mutation scanning.     

Meta-analysis methodology for combining non-parametric sibpair linkage results: genetic homogeneity and identical markers

Meta-analysis methodology is developed for combining sibpair linkage results across multiple studies employing different study designs, some employing quantitative traits (e.g., blood pressure) and some employing qualitative traits (e.g., clinical hypertension), under the assumption that the underlying (disease) trait loci are the same. Pooling results based on three commonly used sibpair methods is considered: the affected sibpair method for dichotomous traits and, for quantitative traits, the Haseman-Elston regression method and the Risch-Zhang extremely discordant sibpair method. The proportion of genes shared identical by descent (IBD) by a sibpair of certain trait outcomes is chosen as a common effect to be pooled across studies. Variation in the observed IBD proportions among individual studies is modeled using a random effects model. A heterogeneity test is provided to assess the variability among individual studies. When results from all three types of studies are available, we derive pooled estimates of IBD proportions both for sibpairs with extremely concordant trait values and for sibpairs with extremely discordant trait values, and construct a combined test of linkage based on the difference of the two estimates. Simulation studies demonstrate the need for and the advantage of meta-analysis of linkage results. We also present some guidelines for reporting linkage studies bearing potential future meta-analysis in mind.     

Aortic valve tumor causing acute myocardial infarction in a child

A 10-year-old child presented with biventricular failure after an acute myocardial infarction. On investigation a large tumor arising from the aortic valve was diagnosed. The patient underwent successful aortic valve replacement for complete excision of the tumor mass, which was reported to be a papillary fibroelastoma. This case report highlights the unusual presentation of an aortic valve tumor in a child with myocardial infarction. The surgical dilemmas of the timing of the operation and the nature of the operation are discussed.     

Correlation of the activity of the key enzymes of glycolysis and respiration in hepatomas with different growth rates

It is shown that an increase in the activity of glycolysis resulting from the rise of the hepatoma growth rate is accompanied by a decrease in the activity of the pentose-phosphate pathway and respiratory chain. It is supposed that variations in the activity both of different carbohydrate catabolism ways and the respiration with a rise of the hepatoma growth rate reflect changes in the relative content of cells at different phases of the cell cycle.     

Displaying content of scientific journals: A co-heading analysis

A co-heading analysis is proposed for representing the subject content of scientific journals. It is based on the subject headings assigned to documents before their input in bibliographic databases. The method utilizes specifically the co-appearance of headings in the document records to display the subject scope of a given journal not only by the topics covered but by their relationships as well. This analysis is applied in superconductivity for displaying the content of some physics journals using data from 1984 Physics Abstracts. The results (in the form of inclusion maps) could help information scientists and library staff in evaluating and selecting appropriate journals.