Detection of the hemoglobin E mutation using the color complementation assay: application to complex genotyping

The color complementation assay (CCA) is a method of allele-specific DNA amplification by which competitive priming and extension of fluorescently labeled oligonucleotide primers determine the color of DNA amplification product. This diagnostic method precludes the need for radioisotopes, electrophoresis, and multiple high-stringency reaction conditions. The multiplicity of mutant globin genes present in Southeast Asians complicates clinical diagnosis and underscores the importance of DNA-based diagnostic methods. We have applied CCA to distinguish beta A and beta E alleles. Competing 15mer primers were a fluorescein-labeled complement to beta A and a rhodamine-labeled complement to beta E, identical except for their central nucleotides. A common unlabeled primer was used to amplify DNA product, the color of which was determined by the perfectly complementary primer. Color photography and spectrofluorometry, as well as a method of black-white photography that we developed to distinguish fluorescein- and rhodamine- labeled DNA, were used to record results. We applied CCA to define the complex genotype of a Thai woman with thalassemia intermedia, 96% HbE, and 4% HbF whose possible genotypes included several permutations of alpha-thalassemia, beta-thalassemia, and beta E genes. zeta-Globin gene mapping of DNA doubly digested with Bg/II and Asp 718 showed the -alpha 3.7/--SEA genotype, and CCA confirmed homozygous beta E/beta E. The CCA is useful for diagnosing the compound hemoglobin genotypes of Southeast Asians and could be applied also to prenatal diagnosis in this population.     

Minimally invasive video-assisted mitral valve repair: short and mid-term results

BACKGROUND AND AIM OF THE STUDY: Port-Access video-assisted surgery for mitral valve repair has become an alternative for mid-sternotomy. However, mid-term results are not yet available. METHODS: Between February 1997 and December 1999, 121 patients underwent mitral valve surgery through a 4- to 5-cm right anterolateral thoracotomy using the Heartport endovascular cardiopulmonary bypass system; among these patients, 77 (57 males, 20 females; mean age 59 years; range 31-84 years) underwent mitral valve repair. Severe (4+) mitral regurgitation (MR) was seen in 63 patients (82%). Mean NYHA class was 2.5+/-0.4. Standard Carpentier mitral valve repair procedures were used in all patients; 11 received PTFE chordae for anterior leaflet prolapse. RESULTS: Pathologies were degenerative (n = 69), chronic endocarditis (n = 4), annular dilatation (n = 3) and rheumatic (n = 1). Hospital mortality was 1.3% (n = 1). Two patients (2.6%) had conversion to sternotomy for aortic dissection caused by the Endo-Aortic Clamp. Nine patients (11%) underwent revision for bleeding. Mean cross-clamp and perfusion times were 103 min (range: 24-160 min) and 140 min (range: 75-215 min), respectively. Mean hospital stay was eight days (range: 4-36 days). During follow up (mean 31 months; range: 17-51 months) all patients improved their NYHA class; eight (11%) remained in class II. Left ventricular (LV) end-diastolic and LV end-systolic diameters decreased from 61+/-7.3 mm to 53+/-6.9 mm (p <0.01) and from 37+/-6.8 mm to 34+/-6.9 mm (p <0.05), respectively. Sixty-two patients (88%) had no or trivial MR, and nine (12%) had moderate MR (2+). There were two late valve replacements for endocarditis, and no late deaths. CONCLUSION: Port-Access mitral valve repair constitutes a valid alternative to the standard procedure, and has good mid-term results. Video-assisted mitral valve repair appears to be safe and reproducible.     

Diagnostic role of an immunoassay-detected polymorphism of factor IX for potential carriers of hemophilia B

In hemophilia B, assays based on a monoclonal antifactor IX specific for the Thr-148 variant of an exonic polymorphism have diagnosed carriers in selected families by either establishing linkage or by indicating the presence or absence of a given normal factor IX. The sensitivity of the immunoassays for detecting heterozygous women was explored by comparing results from immunoassays with solid-phase polyclonal v the monoclonal antifactor IXs. Factor IX with the normal Ala-148 variant gave a flat dilution curve, qualitatively distinct from factor IX with the Thr-148 variant in the monoclonal assay. The two were indistinguishable in the polyclonal assay. Mixtures of equal amounts of the two types gave an intermediate result, about half as reactive in the monoclonal as compared with the polyclonal assay system. Whereas mixtures with 10% Ala-148 and 90% Thr-148 factor IXs could not readily be distinguished from Thr-148 factor IX plasma, as little as 1% of the Thr-148 protein was detected in Ala-148 factor IX plasma. The frequency of the Ala-148 variant varied in individuals with different ethnic backgrounds; it was found in 29% of white, 12% of black, and none of Asian blood donors' factor IX genes in Seattle. Only 4% of samples from South African black men were nonreactive (ie, Ala- 148). The Thr/Ala-148 dimorphism is in strong linkage disequilibrium with Taql restriction fragment length polymorphisms (RFLPs). Three recombinations were noted in normal white genes and one in a normal black factor IX gene (less than 2% of those examined). In 34 white families with at least one woman being a possible carrier, genetically, the immunoassay results were informative in 18. RFLP analyses were informative in eight of the 15 families tested. In five families each, assignment of carrier status was made to a woman by only DNA or only immunoassay results, whereas the other approach was noninformative. The immunoassays provide a rapid, inexpensive screening test and complement DNA analysis in white women who are potential carriers of hemophilia B.     

Competencies of specialised wound care nurses: a European Delphi study

Health care professionals responsible for patients with complex wounds need a particular level of expertise and education to ensure optimum wound care. However, uniform education for those working as wound care nurses is lacking. We aimed to reach consensus among experts from six European countries as to the competencies for specialised wound care nurses that meet international professional expectations and educational systems. Wound care experts including doctors, wound care nurses, lecturers, managers and head nurses were invited to contribute to an e‐Delphi study. They completed online questionnaires based on the Canadian Medical Education Directives for Specialists framework. Suggested competencies were rated on a 9‐point Likert scale. Consensus was defined as an agreement of at least 75% for each competence. Response rates ranged from 62% (round 1) to 86% (rounds 2 and 3). The experts reached consensus on 77 (80%) competences. Most competencies chosen belonged to the domain ‘scholar’ (n = 19), whereas few addressed those associated with being a ‘health advocate’ (n = 7). Competencies related to professional knowledge and expertise, ethical integrity and patient commitment were considered most important. This consensus on core competencies for specialised wound care nurses may help achieve a more uniform definition and education for specialised wound care nurses.     

Anonymity Versus Privacy: Selective Information Sharing in Online Cancer Communities

Background

Active sharing in online cancer communities benefits patients. However, many patients refrain from sharing health information online due to privacy concerns. Existing research on privacy emphasizes data security and confidentiality, largely focusing on electronic medical records. Patient preferences around information sharing in online communities remain poorly understood. Consistent with the privacy calculus perspective adopted from e-commerce research, we suggest that patients approach online information sharing instrumentally, weighing privacy costs against participation benefits when deciding whether to share certain information. Consequently, we argue that patients prefer sharing clinical information over daily life and identity information that potentially compromises anonymity. Furthermore, we explore whether patients’ prior experiences, age, health, and gender affect perceived privacy costs and thus willingness to share information.

Objective

The goal of the present study is to document patient preferences for sharing information within online health platforms.

Methods

A total of 115 cancer patients reported sharing intentions for 15 different types of information, demographics, health status, prior privacy experiences, expected community utility, and privacy concerns.

Results

Factor analysis on the 15 information types revealed 3 factors coinciding with 3 proposed information categories: clinical, daily life, and identity information. A within-subject ANOVA showed a strong preference for sharing clinical information compared to daily life and identity information (F _1,114=135.59, P=.001, η²=.93). Also, adverse online privacy experiences, age, and health status negatively affected information-sharing intentions. Female patients shared information less willingly.

Conclusions

Respondents’ information-sharing intentions depend on dispositional and situational factors. Patients share medical details more willingly than daily life or identity information. The results suggest the need to focus on anonymity rather than privacy in online communities.     

胰腺癌组织VEGF和MVD表达与CT灌注成像的关系

血管内皮生长因子作为肿瘤血管生成的一种主要调控因子,与微血管密度密切相关．胰腺癌组织的血管内皮生长因子和微血管密度的测定对于判断患者的预后,指导临床治疗和判断疗效等具有重要作用．CT灌注成像可以通过无创伤检查反映胰腺癌的肿瘤血管构成, 在治疗前后提供有价值依据,对胰腺癌的诊治有重要意义．     

Automated Network Assembly of Mechanistic Literature for Informed Evidence Identification to Support Cancer Risk Assessment

Background: Mechanistic data is increasingly used in hazard identification of chemicals. However, the volume of data is large, challenging the efficient identification and clustering of relevant data.Objectives: We investigated whether evidence identification for hazard assessment can become more efficient and informed through an automated approach that combines machine reading of publications with network visualization tools.Methods: We chose 13 chemicals that were evaluated by the International Agency for Research on Cancer (IARC) Monographs program incorporating the key characteristics of carcinogens (KCCs) approach. Using established literature search terms for KCCs, we retrieved and analyzed literature using Integrated Network and Dynamical Reasoning Assembler (INDRA). INDRA combines large-scale literature processing with pathway databases and extracts relationships between biomolecules, bioprocesses, and chemicals into statements (e.g., “benzene activates DNA damage”). These statements were subsequently assembled into networks and compared with the KCC evaluation by the IARC, to evaluate the informativeness of our approach.Results: We found, in general, larger networks for those chemicals which the IARC has evaluated the evidence to be strong for KCC induction. Larger networks were not directly linked to publication count, given that we retrieved small networks for several chemicals with little support for KCC activation according to the IARC, despite the significant volume of literature for these specific chemicals. In addition, interpreting networks for genotoxicity and DNA repair showed concordance with the IARC KCC evaluation.Discussion: Our method is an automated approach to condense mechanistic literature into searchable and interpretable networks based on an a priori ontology. The approach is no replacement of expert evaluation but, instead, provides an informed structure for experts to quickly identify which statements are made in which papers and how these could connect. We focused on the KCCs because these are supported by well-described search terms. The method needs to be tested in other frameworks as well to demonstrate its generalizability. https://doi.org/10.1289/EHP9112