The challenges of litigation in US courts and the actions tissue banks can take to meet those challenges

The growth of tissue banking from local non-profit organizations to national and multi-national corporations has increased the likelihood of litigation against tissue banks. The acquisition of tissue banks by corporate entities, many of whom are based in the US, means that tissue banks need to be prepared for the challenge of litigation in the US courts. The purpose of this paper is to help tissue banks meet those challenges by describing the nature of US litigation, the most common types of lawsuits against tissue banks and the steps that tissue banks can take to prepare for litigation in the US.     

Efficiency of population structures for mapping of Mendelian and imprinted quantitative trait loci in outbred pigs using variance component methods

In a simulation study different designs for a pure line pig population were compared for efficiency of mapping QTL using the variance component method. Phenotypes affected by a Mendelian QTL, a paternally expressed QTL, a maternally expressed QTL or by a QTL without an effect were simulated. In all alternative designs 960 progeny were phenotyped. Given the limited number of animals there is an optimum between the number of families and the family size. Estimation of Mendelian and parentally expressed QTL is more efficient in a design with large family sizes. Too small a number of sires should be avoided to minimize chances of sires to be non-segregating. When a large number of families is used, the number of haplotypes increases which reduces the accuracy of estimating the QTL effect and thereby reduces the power to show a significant QTL and to correctly position the QTL. Dense maps allow for smaller family size due to exploitation of LD-information. Given the different possible modes of inheritance of the QTL using 8 to16 boars, two litters per dam was optimal with respect to determining significance and correct location of the QTL for a data set consisting of 960 progeny. The variance component method combining linkage disequilibrium and linkage analysis seems to be an appropriate choice to analyze data sets which vary in marker density and which contain complex family structures.     

Purification and characterization of hemolymph juvenile hormone esterase from the cricket, Gryllus assimilis.

Juvenile hormone esterase (JHE) from the serum of the cricket, Gryllus assimilis, was purified to homogeneity in a four-step procedure involving polyethylene glycol precipitation, hydrophobic interaction FPLC, and ion exchange FPLC. This procedure could be completed in 4 days and resulted in a greater than 900-fold purification with greater than 30% recovery. The purified enzyme exhibited a single band on a silver-stained SDS PAGE gel and had an apparent subunit molecular mass of 52 kDa. The native subunit molecular mass, determined by gel permeation FPLC, was 98 kDa, indicating that JHE from Gryllus assimilis is a dimer of two identical or similar subunits. The turnover number of the purified enzyme (1.41 s(-1)), K(M(JH-III)) (84 +/- 12 nM) of nearly-purified enzyme, and k(cat)/K(M) (1.67 x 10(7) s(-1) M(-1)) were similar to values reported for other well-established lepidopteran and dipteran JHEs. JHE from Gryllus assimilis was strongly inhibited by the JHE transition-state analogue OTFP (octylthio-1,1,1-trifluoro-2-propanone; I(50) = 10(-7) M) and by DFP (diisopropyl fluorophosphate; I(50) = 10(-7) M). The shapes of the inhibition profiles suggest the existence of multiple binding sites for these inhibitors or multiple JHEs that differ in inhibition. Isoelectric focusing separated the purified protein into 4 isoforms with pIs ranging from 4.7-4.9. N-terminal amino acid sequences (11-20 amino acids) of the isoforms differed from each other in 1-4 positions, suggesting that the isoforms are products of the same or similar genes. Homogeneously purified JHE hydrolyzed alpha-napthyl esters, did not exhibit any detectable acetylcholinesterase, acid phosphatase, or aminopeptidase activity, and exhibited only very weak alkaline phosphatase activity. JHE exhibited a low (11 microM) K(M) for long-chain alpha-naphthyl esters, indicating that JHE may have physiological roles other than the hydrolysis of JH-III. Purification of JHE represents a key step in our attempts to identify the molecular causes of genetically-based variation in JHE activity in G. assimilis. This represents the first homogeneous purification of JHE from a hemimetabolous insect.     

拉萨高原居民肺容量的测定

对年龄、身高和体重相同的拉萨男性世居藏族39人和男性移居汉族43人的肺容量进行了测定。结果显示:藏族组的肺活量(VC)、肺总容量、胸围均大于汉族组,残气量有大于汉族组之趋势(P=0.06)。胸围的大小与VC呈正相关。5岁前和18岁后移居高原者之肺容量无差别。结果提示,拉萨世居藏族具有较大的肺容量,这对提高肺弥散功能和维持运动时的血氧饱和度有重要意义。     

A change in twist of actin provides the force for the extension of the acrosomal process in limulus sperm: the false-discharge reaction

One of the most spectacular motions is the generation of the acrosomal process in the limulus sperm. On contact with the egg, the sperm generates a 60-mum-long process that literally drills its way through the jelly surrounding the egg. This irresversible reaction takes only a few seconds. We suggested earlier that this motion is driven by a change in twist of the actin filaments comprising the acrosomal process. In this paper we analyze the so-called false discharge, a reversible reaction, in which the acrosomal filament bundle extends laterally from the base of the sperm and not anteriorly from the apex. Unlike the true discharge, which is straight, the false discharge is helical. Before extension, the filament bundle is coiled about the base of the sperm. In the coil, the bundle is not smoothly bent but consists of arms (straight segments) and elbows (corners) so that the coil looks like a 14-sided polygon. The extension of the false discharge works as follows: starting at the base of the bundle, the filaments change their twist which concomitantly changes the orientations of the elbows relative to each other; that is, in the coil, the elbows all like in a common plane, but after the change in twist, the plane of each elbow is rotated to be perpendicular to that of its neighbors. This change transforms the bundle from a compact coil into an extended left- handed helix. Because the basal end of the bundle is unconstrained, the extension is lateral. The true discharge works the same way but starts at the apical end of the bundle. The apical end, however, is constrained by its passage through the nuclear canal, which directs the extention anteriorly. Unlike the false discharge, during the true discharge the elbows are melted out, making the reaction irreversible. This study shows that rapid movement can be regenerated by actin without myosin and gives us insight into the molecular mechanism.     

Iodination of a tyrosyl residue in staphylococcal alpha-toxin.

Iodination of staphylococcal alpha-toxin by the lactoperoxidase method resulted in the maximal incorporation of about 2.5 atoms of iodine per molecule of alpha-toxin. The iodination primarily involved a single tyrosine residue as shown by analysis of both cyanogen bromide and tryptic peptides. Iodination at a level of 1.2 iodine atoms per alpha-toxin molecule led to a dramatic decrease in the hemolytic and lethal activities, although no decrease in the binding of iodinated toxin to rabbit erythrocytes was observed (Cassidy and Harshman (1976), Biochemistry, the following paper in this issue). Monoiodinated alpha-toxin was found to have 15% of the specific hemolytic activity of native alpha-toxin. Incubation of rabbit erythrocytes with iodinated alpha-toxin led to a significant protection from the hemolytic activity of native alpha-toxin added later. The results show the modification of a single unique tyrosyl residue in alpha-toxin permits the resolution of alpha-toxin's biological activities from its cell binding activity.     

Increase in plasma membrane phosphodiesterase activity in contact-inhibited 3T3 cells and in phenotypically reverted SV-3T3 cells

Summary Contact-inhibited 3T3 mouse fibroblast cells, in contrast to logarithmically growing 3T3 cells and SV-3T3 transformed cells, have increased levels of plasma membranebound phosphodiesterase (oligonucleotidase, E.C. 3.1.4.19; nucleotide pryrophosphatase, E.C. 3.6.1.9) activity. The increase in enzyme, recorded as increased specific activity, is reversible, as evidenced by the return to normal values following dilution of confluent 3T2 cells and re-initiation of growth. Increased enzyme activity is induced again when the cells regain the confluent state. Transformed SV-3T3 cells can be induced to mimic the contact inhibited state, including increased plasma membrane phosphodiesterase activity, by exposure to a combination of: (i) agents that are known to induce increased intracellular cAMP levels and (ii) additions of purified 3T3 or SV-3T3 plasma membranes. Additions of either alone fails to induce the increase in membrane phosphodiesterase activity, although each alone can significantly suppress cell growth, as measured by incorporation of³H amino acids.We suggest that the elevation of plasma membrane phosphodiesterase activity may serve as a measure of conversion to the contact-inhibited state in both normal cells and phenotypically reverted transformed cells.     

The <Emphasis Type="Italic">Mycobacterium marinum mel2</Emphasis> locus displays similarity to bacterial bioluminescence systems and plays a role in defense against reactive oxygen and nitrogen species

Background  

Mycobacteria have developed a number of pathways that provide partial protection against both reactive oxygen species (ROS) and reactive nitrogen species (RNS). We recently identified a locus in Mycobacterium marinum, mel2, that plays a role during infection of macrophages. The molecular mechanism of mel2 action is not well understood.     

Regulation of juvenile hormone esterase gene expression in the tobacco budworm (Heliothis virescens)

The tissue distribution, developmental control, and induction of juvenile hormone esterase (JHE) mRNA was examined in Heliothis virescens using an 800-base pair fragment of a JHE cDNA clone. Northern hybridization analysis of poly(A)+RNA from fat body and integument of fifth stadium larvae indicated the presence of a single JHE mRNA species having an estimated length of 3 kilobases. On Day 2 of the fifth stadium (L5D2), basal JHE mRNA levels were 3-fold higher in the integument than the fat body, which correlated with the higher specific activity of the enzyme in the integument at this time. However, JHE mRNA levels in the fat body on Day 4 of the fifth stadium were 9-fold higher than on Day 2, while mRNA levels in the integument remained the same. This endogenous increase in JHE mRNA and activity in the fat body occurred at the time of peak hemolymph JHE activity. JHE mRNA was not detected in third stadium larvae which have very low levels of JHE activity. Treatment of L5D2 larvae with the juvenile hormone mimic epofenonane resulted in a 7- and 14-fold increase in the level of JHE mRNA in the integument and fat body, respectively. The mRNA induced in both tissues was of the same estimated length as the constitutively expressed message. The data indicate that the developmental regulation and induction of JHE can occur at the level of mRNA. There is evidence that the fat body secretes more JHE than does the integument and could be the major source of hemolymph JHE.