Physicians' duty to recontact and update genetic advice.

This perspective addresses whether physicians have a duty to recontact former or current patients to update clinical advice based on newly discovered genomic information. Genetic information is unique compared with other medical data in that the underlying data do not appreciably change during the patients' lifetime, but the clinical significance of that information will continue to evolve. Based on relevant case law and guidelines, there is no general, established legal duty for physicians to affirmatively recontact former or current patients to update clinical advice based on newly discovered genetic information. However, integration of genomics into clinical practice is advancing quickly, and there may be limited, specific situations where a physician may have a duty to provide updated genetic information.

A new window of opportunity to reject process-based biotechnology regulation.

The question of whether biotechnology regulation should be based on the process or the product has long been debated, with different jurisdictions adopting different approaches. The European Union has adopted a process-based approach, Canada has adopted a product-based approach, and the United States has implemented a hybrid system. With the recent proliferation of new methods of genetic modification, such as gene editing, process-based regulatory systems, which are premised on a binary system of transgenic and conventional approaches, will become increasingly obsolete and unsustainable. To avoid unreasonable, unfair and arbitrary results, nations that have adopted process-based approaches will need to migrate to a product-based approach that considers the novelty and risks of the individual trait, rather than the process by which that trait was produced. This commentary suggests some approaches for the design of such a product-based approach.

Comparison of a new prototype immunochromatographic assay and a commercial enzyme-linked immunosorbent assay for the detection of serum antibodies against Toscana virus.

Toscana virus (TOSV) is an arthropod-borne virus, transmitted to humans by Phlebotomus spp. Sandflies, which causes neurological diseases such as aseptic meningitis and meningoencephalitis. The commercial enzyme-linked immunosorbent assay (ELISA) is used widely to detect anti-TOSV IgG and IgM antibodies and to allow for rapid diagnosis of infection (Diesse Diagnostica Senese, Siena, Italy). Recently, an immunochromatographic assay (ICA) was developed for human anti-TOSV IgG or IgM detection by InBios International (Seattle, WA, USA). A comparison of the two diagnostic assays was performed on one hundred serum samples collected from patients hospitalized with suspected TOSV meningitis. Both assays were in excellent agreement, for both IgG and IgM detection. For IgM, 64/65 ELISA positive samples were positive by ICA. One serum, positive for specific IgM by ELISA but negative by ICA, was confirmed by direct diagnosis, with TOSV RNA detection in the patient's cerebrospinal fluid by PCR. For IgG, 64 samples were positive by ICA out of 71 ELISA positive samples. The discordant sera were positive by immunofluorescence and neutralization tests. Three out of these seven samples were also positive by IgM ICA. The sensitivity of these new assays compared to ELISA, which is used routinely, was 98.5% for IgM and 90.1% for IgG, while specificity was 100% in both cases. This data shows that ICA could be a reliable alternative test for serological diagnosis of TOSV infection in humans.

Lateral flow immunoassay for diagnosis of Trypanosoma cruzi infection with high correlation to the radioimmunoprecipitation assay.

The incidence of blood donors seropositive for Trypanosoma cruzi in North America has increased with population migration and more rigorous surveillance. The United States, considered nonendemic for T. cruzi, could therefore be at risk to exposure to parasite transmission through blood or organ donations. Current tests show variable reactivity, especially with Central American sera. Here we describe the development of a lateral flow immunoassay for the rapid detection of T. cruzi infection that has a strong correlation to the radioimmunoprecipitation assay (RIPA) "gold standard" in the United States. Such a test could have utility in small blood banks for prescreening donors, as well as in cardiac transplantation evaluation. T. cruzi consensus and/or RIPA-positive sera from Central and South America were evaluated in enzyme immunoassays (EIAs). These included commercial panels from Boston Biomedica, Inc. (BBI) (n = 14), and HemaBio (n = 21). Other sources included RIPA-positive sera from the American Red Cross (ARC) (n = 42), as well as from Chile. Sera were tested with the multiepitope recombinant TcF. All but one of the BBI samples were positive and 7 of 21 HemaBio samples and 6 of 42 ARC samples were low positive or negative. This observation indicated the need for additional antigens. To complement TcF reactivity, we tested the sera with peptides 30, 36, SAPA, and 1.1, 1.2, and 1.3 His fragments of 85-kDa trans-sialidase. We identified a promising combination of the tested antigens and constructed a single recombinant protein, ITC6, that enhanced the relative sensitivity in U.S. blood donor sera compared to that of TcF. The data on its evaluation using RIPA-confirmed positive sera in EIA and lateral flow immunoassay studies are presented, along with an additional recombinant protein, ITC8.2, with two additional sequences for peptide 1 and Kmp-11. The latter, when evaluated in a dipstick assay with consensus positive sera, had a sensitivity of 99.2% and a specificity of 99.1%.

Adenosine kinase deficiency is associated with developmental abnormalities and reduced transmethylation.

Adenosine (Ado) kinase (ADK; ATP:Ado 5' phosphotransferase, EC 2.7.1.20) catalyzes the salvage synthesis of adenine monophosphate from Ado and ATP. In Arabidopsis, ADK is encoded by two cDNAs that share 89% nucleotide identity and are constitutively, yet differentially, expressed in leaves, stems, roots, and flowers. To investigate the role of ADK in plant metabolism, lines deficient in this enzyme activity have been created by sense and antisense expression of the ADK1 cDNA. The levels of ADK activity in these lines range from 7% to 70% of the activity found in wild-type Arabidopsis. Transgenic plants with 50% or more of the wild-type activity have a normal morphology. In contrast, plants with less than 10% ADK activity are small with rounded, wavy leaves and a compact, bushy appearance. Because of the lack of elongation of the primary shoot, the siliques extend in a cluster from the rosette. Fertility is decreased because the stamen filaments do not elongate normally; hypocotyl and root elongation are reduced also. The hydrolysis of S-adenosyl-L-homo-cysteine (SAH) produced from S-adenosyl-L-methionine (SAM)-dependent methylation reactions is a key source of Ado in plants. The lack of Ado salvage in the ADK-deficient lines leads to an increase in the SAH level and results in the inhibition of SAM-dependent transmethylation. There is a direct correlation between ADK activity and the level of methylesterified pectin in seed mucilage, as monitored by staining with ruthenium red, immunofluorescence labeling, or direct assay. These results indicate that Ado must be steadily removed by ADK to prevent feedback inhibition of SAH hydrolase and maintain SAM utilization and recycling.