Forensic DNA data banking by state crime laboratories.

This article reports the results of a survey of the responsible crime laboratories in the first 19 states with legislation establishing forensic DNA data banks. The survey inquired into the labs' policies and procedures regarding the collection, storage, and analysis of samples; the retention of samples and data; search protocols; access to samples and data by third parties; and related matters. The research suggests that (1) the number of samples collected from convicted offenders for DNA data banking has far surpassed the number that have been analyzed; (2) data banks have already been used in a small but growing number of cases, to locate suspects and to identify associations between unresolved cases; (3) crime labs currently plan to retain indefinitely the samples collected for their data banks; and (4) the nature and extent of security safeguards that crime labs have implemented for their data banks vary among states. The recently enacted DNA Identification Act (1994) will provide $40 million in federal matching grants to states for DNA analysis activities, so long as states comply with specified quality-assurance standards, submit to external proficiency testing, and limit access to DNA information. Although these additional funds should help to ease some sample backlogs, it remains unclear how labs will allocate the funds, as between analyzing samples for their data banks and testing evidence samples in cases without suspects. The DNA Identification Act provides penalties for the disclosure or obtaining of DNA data held by data banks that participate in CODIS, the FBI's evolving national network of DNA data banks, but individual crime labs must also develop stringent internal safeguards to prevent breaches of data-bank security.     

A global review of species-specific shark-fin-to-body-mass ratios and relevant legislation

In this review, shark-fin-to-body-mass ratios, which have been legislated by several countries as a means of regulating and monitoring shark fisheries, have been compiled and reviewed. Observed and legislated wet-fin-mass-to-round-mass (M(fw) :M(r) ) ratios have been collected for 50 species and eight countries. Wet to dry-fin mass conversion factors have also been reviewed. Existing shark fishery legislation was compiled by political entity and regional fishery management organizations (RFMO). The mean observed M(fw) :M(r) ratio for all species was 3·0%, but actual fin to body-mass ratios varied considerably by species and location. Species-specific mean ratios ranged from 1·1 to 10·9%, and estimated mean ratios ranged from 1·5 to 6·1% by country, depending on fin-cutting practices and the mix of exploited species. The mean conversion factor for wet to dry-fin mass was 0·43. Shark-related legislation was found to exist in 37 countries and the 22 maritime members of the European Union, and shark-related regulations have been designated by nine RFMOs. Results suggest that currently regulated ratios may not be appropriate for all species and fin-cutting practices, and regulations based on generalized ratios for all sharks may be inadequate. Alternative policies may be necessary for the effective management of global shark fisheries.     

DNA fingerprinting for forensic identification: potential effects on data interpretation of subpopulation heterogeneity and band number variability

Some methods of statistical analysis of data on DNA fingerprinting suffer serious weaknesses. Unlinked Mendelizing loci that are at linkage equilibrium in subpopulations may be statistically associated, not statistically independent, in the population as a whole if there is heterogeneity in gene frequencies between subpopulations. In the populations where DNA fingerprinting is used for forensic applications, the assumption that DNA fragments occur statistically independently for different probes, different loci, or different fragment size classes lacks supporting data so far; there is some contrary evidence. Statistical association of alleles may cause estimates based on the assumption of statistical independence to understate the true matching probabilities by many orders of magnitude. The assumptions that DNA fragments occur independently and with constant frequency within a size class appear to be contradicted by the available data on the mean and variance of the number of fragments per person. The mistaken use of the geometric mean instead of the arithmetic mean to compute the probability that every DNA fragment of a randomly chosen person is present among the DNA fragments of a specimen may substantially understate the probability of a match between blots, even if other assumptions involved in the calculations are taken as correct. The conclusion is that some astronomically small probabilities of matching by chance, which have been claimed in forensic applications of DNA fingerprinting, presently lack substantial empirical and theoretical support.     

A systematic review of re-identification attacks on health data

BackgroundPrivacy legislation in most jurisdictions allows the disclosure of health data for secondary purposes without patient consent if it is de-identified. Some recent articles in the medical, legal, and computer science literature have argued that de-identification methods do not provide sufficient protection because they are easy to reverse. Should this be the case, it would have significant and important implications on how health information is disclosed, including: (a) potentially limiting its availability for secondary purposes such as research, and (b) resulting in more identifiable health information being disclosed. Our objectives in this systematic review were to: (a) characterize known re-identification attacks on health data and contrast that to re-identification attacks on other kinds of data, (b) compute the overall proportion of records that have been correctly re-identified in these attacks, and (c) assess whether these demonstrate weaknesses in current de-identification methods.ConclusionsThe current evidence shows a high re-identification rate but is dominated by small-scale studies on data that was not de-identified according to existing standards. This evidence is insufficient to draw conclusions about the efficacy of de-identification methods.     

Quality issues in tissue banking:Quality management systems - A review

The situation in tissue banking changed radically and fundamentally at the beginning of the 1990s. The essential causes are on the one hand, the continually increasing demand for human cells and tissue and other biological material for clinical use and research, and on the other hand, the rapid progress in the medical, technical and natural sciences. Biotechnology in particular, has profited from this. Modern tissue banks could no longer be imagined without its methods.A consequence of these developments and a prerequisite for the fulfilment of the derived requirements is the necessity for national and international cooperation as well as the harmonisation of ethical principles and quality assurance standards and regulations (von Versen (1999) Ann Chir Gynaecol 88: 215-220). The introduction of an all-encompassing Quality Management System (QMS) is a suitable instrument for this purpose.After the presentation of explanations and definitions of quality terminology, this article describes the use of the international standard ISO 9000 as a general QMS, which embraces both the specific methodology as well as the general aspects of Quality Management (research and development, design control, education and training, documentation, traceability, management control, corrective action, etc.) in tissue banking. The individual elements of this system are explained and selected examples are described. The authors look upon this QMS as an indispensable instrument for harmonisation and international cooperation in tissue banking.Finally, the use of such a standard would be a positive sign to the regulatory authorities and the public that tissue banking is making a visible effort to introduce a world-class QMS in its operations.     

Chloroplast DNA systematics: a review of methods and data analysis

The field of plant molecular systematics is expanding rapidly, and with it new and refined methods are coming into use. This paper reviews recent advances in experimental methods and data analysis, as applied to the chloroplast genome. Restriction site mapping of the chloroplast genome has been used widely, but is limited in the range of taxonomic levels to which it can be applied. The upper limits (i.e., greatest divergence) of its application are being explored by mapping of the chloroplast inverted repeat region, where rates of nucleotide substitution are low. The lower limits of divergence amenable to restriction site study are being examined using restriction enzymes with 4-base recognition sites to analyze polymerase chain reaction (PCR)-amplified portions of the chloroplast genome that evolve rapidly. The comparison of DNA sequences is the area of molecular systematics in which the greatest advances are being made. PCR and methods for direct sequencing of PCR products have resulted in a mushrooming of sequence data. In theory, any degree of divergence is amenable to comparative sequencing studies. In practice, plant systematists have focused on two slowly evolving sequences (rbcL and rRNA genes). More rapidly evolving DNA sequences, including rapidly changing chloroplast genes, chloroplast introns, and intergenic spacers, and the noncoding portions of the nuclear ribosomal RNA repeat, also are being investigated for comparative purposes. The relative advantages and disadvantages of comparative restriction site mapping and DNA sequencing are reviewed. For both methods, the analysis of resulting data requires sufficient taxon and character sampling to achieve the best possible estimate of phylogenetic relationships. Parsimony analysis is particularly sensitive to the issue of taxon sampling due to the problem of long branches attracting on a tree. However, data sets with many taxa present serious computational difficulties that may result in the inability to achieve maximum parsimony or to find all shortest trees.     

Elasmobranch color change: A short review and novel data on hormone regulation.

Skins of Potamotrygon reticulatus are light in color in vitro, exhibiting punctate melanophores. Alpha-Melanocyte stimulating hormone (EC(50) = 4.58 x 10(-9) M) and prolactin (EC(50) = 1.44 x 10(-9) M) darken the skins in a dose-dependent manner. The endothelins ET-1, ET-2 and ET-3, and the purines, ATP, and uracil triphosphate (UTP) were not able to induce either skin lightening or darkening. Forskolin and the calcium ionophore A23187 promoted a dose-dependent darkening response, whereas N(2), 2'-O-dibutyryl guanosine 3'-5'-cyclic monophosphate (db cyclic GMP), phorbol-12-myristate-13-acetate (TPA), and 1-oleoyl-2-acetyl-sn-glycerol (OAG) were ineffective. The maximal response obtained with the calcium ionophore A23187 was only 76% of maximal darkening. These results indicate that the cyclic adenosine 3'-5'-monophosphate (cAMP) pathway is probably involved in the pigment dispersion of P. reticulatus melanophores. Other experiments should be done to further investigate how cytosolic calcium may be physiologically increased, and the existence of a putative cross-talk between calcium and cAMP signals. In conclusion, the only hormones effective on P. reticulatus melanophores were prolactin and alpha-MSH. No aggregating agent has been shown to antagonize these actions. Prolactin effect on elasmobranch melanophores adds a novel physiological role to this ancient hormone. J. Exp. Zool. 284:485-491, 1999.     

Pharmacogenetics: the bioethical problem of DNA investment banking

Concern about the ethics of clinical drug trials research on patients and healthy volunteers has been the subject of significant ethical analysis and policy development--protocols are reviewed by Research Ethics Committees and subjects are protected by informed consent procedures. More recently attention has begun to be focused on DNA banking for clinical and pharmacogenetics research. It is, however, surprising how little attention has been paid to the commercial nature of such research, or the unique issues that present when subjects are asked to consent to the storage of biological samples. Our contention is that in the context of pharmacogenetic add-on studies to clinical drug trials, the doctrine of informed consent fails to cover the broader range of social and ethical issues. Applying a sociological perspective, we foreground issues of patient/subject participation or 'work', the ambiguity of research subject altruism, and the divided loyalties facing many physicians conducting clinical research. By demonstrating the complexity of patient and physician involvement in clinical drug trials, we argue for more comprehensive ethical review and oversight that moves beyond reliance on informed consent to incorporate understandings of the social, political and cultural elements that underpin the diversity of ethical issues arising in the research context.     

Real-time DNA quantification of nuclear and mitochondrial DNA in forensic analysis

The rapid development of molecular genetic analysis tools has made it possible to analyze most biological materialfound at the scene of a crime. Evidence materials containing DNA quantities too low to be analyzed using nuclear markers can be analyzed using the highly abundant mtDNA. However, there is a shortage of sensitive nDNA and mtDNA quantification assays. In this study, an assay for the quantification of very small amounts of DNA, based on the real-time Taq-Man assay, has been developed. This analysis will provide an estimate of the total number of nDNA copies and the total number of mtDNA molecules in a particular evidence material. The quantification is easy to perform, fast, and requires a minimum of the valuable DNA extracted from the evidence materiaL The results will aid in the evaluation of whether the specific sample is suitable for nDNA or mtDNA analysis. Furthermore, the optimal amount of DNA to be used in further analysis can be estimated ensuring that the analysis is successful and that the DNA is retained for future independent analysis. This assay has significant advantages over existing techniques because of its high sensitivity, accuracy, and the combined analysis of nDNA and mtDNA. Moreover, it has the potential to provide additional information about the presence of inhibitors in forensic samples. Subsequent mitochondrial and nuclear analysis of quantified samples illustrated the potential to predict the number of DNA copies required for a successful analysis in a certain typing assay.     

Long-term data storage in DNA.

This article discusses how DNA might be used to store data. It is argued that, at present, DNA would be best employed as a long-term repository (thousands or millions of years). How data-containing DNA might be packaged and how the data might be encrypted, with particular attention to the encryption of written information, is also discussed. Various encryption issues are touched on, such as how data-containing DNA might be differentiated from genetic material, error detection, data compression and reading frame location. Finally, this article broaches the difficulty of constructing very large pieces of DNA in the laboratory and highlights some complications that might arise when attempting to transmit DNA-encrypted data to recipients who are a long period of time in the future.