Early indicators of immunotoxicity: development of molecular biological test batteries.
Explore the source record for details and available documents.
Animals↗
SEARCH · PubMed Health
Results for “molecular testing”
Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
[Molecular genetic testing in endogenous psychoses: the outlook for its use from the viewpoint of medical ethics].
Explore the source record for details and available documents.
DNA↗
[Molecular genetic testing in the diagnosis of sporadic cases of Huntington's chorea].
Huntington's disease is characterized by autosomal dominant transmission and a complete penetrance of the mutant gene. Mutation in Huntington's disease consists in expansion of the unstable tandem CAG-trinucleotide repeats. This discovery allowed to perform a precise DNA diagnosis of the mutant gene carriers. Direct DNA diagnosis has a special importance in sporadic cases of the disease. We performed direct DNA diagnosis in 4 patients with sporadic choreic hyperkinesis, and elaborated a modified protocol for DNA amplification. The obtained results are discussed from the viewpoint of current knowledge about the nature of the Huntington's disease gene.
Aged↗
Ensuring accurate molecular genetic testing.
Explore the source record for details and available documents.
Factor V↗
Molecular electronics. Synthesis and testing of components.
Molecular electronics involves the use of single or small packets of molecules as the fundamental units for computing. While initial targets are the substitution of solid-state wires and devices with molecules, long-range goals involve the development of novel addressable electronic properties from molecules. A comparison of traditional solid-state devices to molecular systems is described. Issues of cost and ease of manufacture are outlined, along with the syntheses and testing of molecular wires and devices.
Computer Systems↗
Post-genome molecular diagnostics in obstetrics.
PURPOSE OF REVIEW: The intention of this review is to familiarize the practicing clinician with the current status and future direction of molecular testing in obstetrics. As a discipline, obstetrics and gynecology is unique in that it deals with the full spectrum of molecular genetic testing. This spectrum includes infectious disease, neoplasia and inherited diseases. This review will focus on inherited conditions and complex diseases, as it is in this context that we may fully realize the true promise of the human genome and its application to the practice of medicine. RECENT FINDINGS: Despite the successful sequencing of the human genome, very few new molecular genetic tests have become available. The apparent reason for this lies in the relative paucity of information gleaned from examining the genes themselves. Two new avenues of investigation are presently underway to improve the 'infirmity' of this information archive. Rather than merely looking at differential gene expression, clinician scientists have begun to examine genetic polymorphisms of single and multiple genes within and between individuals in an attempt to explain biologic processes, including disease states. The second avenue involves the characterization of the products of gene expression--proteins. Proteomics, in conjunction with high throughput polymorphism analysis, may enable us to diagnose and treat complex multifactorial diseases. SUMMARY: Molecular diagnostics for multifactorial diseases will become conceptually and technologically more complex than present DNA testing modalities. The development and ultimate acceptance of these tests will require greater coordination between the medical and scientific communities to ensure that the right technologies are applied to the highest quality samples to answer the most relevant questions.
Female↗
Afirma genomic sequencing classifier performance in young patients with cytologically indeterminate thyroid nodules.
CONTEXT: The Afirma Genomic Sequencing Classifier (GSC) is validated in patients ≥ 21 years with a 96% negative predictive value for malignancy when GSC-(B)enign. Afirma GSC has not been formally studied in patients <21 years of age with indeterminate thyroid nodules (ITNs). OBJECTIVE: To evaluate Afirma GSC in young patients with ITNs. DESIGN: Retrospective analysis of Afirma GSC testing. SETTING: ITNs referred for molecular testing in a real-world setting. PARTICIPANTS: Forty-nine ITNs from 49 patients < 21 years of age who had histopathology or 2 years' clinical follow-up data ascertained. INTERVENTION: None. MAIN OUTCOME MEASURE: Afirma GSC test performance. RESULTS: In 49 ITNs from patients aged 9 to 20 years (median 18.5 [interquartile range, 17.3-19.8]), 30 were GSC-B and 19 GSC-(S)uspicious, among which 14 (73.7%) were malignant (ie, true positive) and 5 (26.3%) were benign (ie, false positive). All 30 Afirma GSC-B cases were either histologically (n = 9) or clinically benign (n = 21) (ie, true negative). All 14 malignancies were GSC-S (sensitivity 100% [95% CI, 77-100]); 30/35 clinically or histologically benign cases were GSC-B (specificity 86% [95% CI, 70-95]). Negative predictive value for an Afirma GSC-B result was 100% [95% CI, 88-100]. Genomic alterations were not detected in the 30 GSC-B samples. Among the 14 malignant samples, there were 9 papillary thyroid carcinomas, 1 oncocytic carcinoma, 1 noninvasive follicular thyroid neoplasm with papillary-like nuclear features, and 3 follicular thyroid carcinomas. CONCLUSION: In young patients with ITNs, the Afirma GSC demonstrated an excellent negative predictive value when defining a thyroid nodule result by histology or clinical follow-up.
Thyroid Nodule↗
From molecular diagnostics to personalized testing.
Gene-based molecular diagnostics is changing the practice of medicine and will continue to do so for the foreseeable future. The major underlying principle of these diagnostic tests is the use of specific nucleic acid sequences as surrogates; amplification of the surrogate markers enables the detection of pathogens or disease-related gene mutations. Gene targets can be amplified by target-, probe- or signal-based methods. Combined use of nucleic acid amplification and enzyme-linked immunosorbent assay with methods such as immuno-polymerase-chain reaction allows us to detect protein at femtogram (10(15) g) levels. A variety of choices are available for the detection of amplified amplicons with the fluorophore-linked nanoparticles as the most sensitive markers. The unique advantages of using covalently-linked nanoparticles include the detection of single molecules, the ability to enrich molecules of interest with unprecedented detection sensitivity (up to zeptogram levels, 10(21) g) and the flexibility of multiple functionalization. Automation appears to be the current trend for high-volume molecular testing of infectious diseases. Molecular profiling of various diseases using genomic or proteomic approaches opens up a molecule wonderland with promise and emergence of new molecular testing that will likely impact the practice of medicine to a greater degree in the future. The future of molecular-based testing and the journey toward personalized testing will be discussed.
Animals↗
Molecular markers of gliomas: a clinical approach.
Over the last decade, the knowledge on the molecular genetic background of gliomas has dramatically increased. This information provides the basis for the molecular target therapies and molecular tests serve to complement the subjective nature of histopathologic criteria and add useful data regarding response to treatments and prognosis. In particular, the use of loss of heterozygosity (LOH) and methylation specific polymerase chain reaction (PCR) (MSP) based testing of gliomas is already in place and used clinically in several centers. This paper provides a brief overview of these molecular genetic aberrations and discusses the clinical utility, as well as the advantages and disadvantages of such approach. Newly developed molecular techniques, such as LOH testing, fluorescence in situ hybridization (FISH), DNA sequencing and MSP, are currently being employed in assessment of gliomas in some laboratories. However, the clinical use of some markers and the context in which the information obtained should be used are still not entirely understood. Therefore, this paper will focus on validation and implementation of molecular testing in gliomas, with emphasis on LOH on chromosomes 1p, 19q, 17p and 10q and O(6)-methylguanine-DNA methyltransferase (MGMT) methylation status.
Biomarkers, Tumor↗
A molecular-based magnet test for malaria.
The molecular-based magnet test for malaria is shown to be more sensitive than the thin blood film test. The globally used thin blood film test is less sensitive because it uses preparation steps that result in the reduction of the absolute number of diagnostically pertinent erythrocytes. Several reports of diagnostic error with the thin film test and the thick film test have appeared in the literature. In marked contrast to the commonly accepted tests, the magnet test concurrently partitions and concentrates the infected erythrocytes present in the initial sample. The magnetic test permits a brief and sensitive microscopic-based enumeration of the malaria-infected erythrocytes in the enriched sample. Diagnostically pertinent hemozoin is simply identified through two of its specific molecular properties: paramagnetism and birefringence. The former property mediates the capture and enrichment of malaria-infected erythrocytes within the magnetic flux and the latter property manifests the characteristic birefringence demonstrated by polarized light.
Animals↗
Combined cytogenetic and molecular analyses for the diagnosis of Prader-Willi/Angelman syndromes.
Prader-Willi (PWS) and Angelman (AS) are syndromes of developmental impairment that result from the loss of expression of imprinted genes in the paternal (PWS) or maternal (AS) 15q11-q13 chromosome. Diagnosis on a clinical basis is difficult in newborns and young infants; thus, a suitable molecular test capable of revealing chromosomal abnormalities is required. We used a variety of cytogenetic and molecular approaches, such as, chromosome G banding, fluorescent in situ hybridization, a DNA methylation test, and a set of chromosome 15 DNA polymorphisms to characterize a cohort of 27 PWS patients and 24 suspected AS patients. Molecular analysis enabled the reliable diagnosis of 14 PWS and 7 AS patients, and their classification into four groups: (A) 6 of these 14 PWS subjects (44 %) had deletions of paternal 15q11-q13; (B) 4 of the 7 AS patients had deletions of maternal 15q11-q13; (C) one PWS patient (8 %) had a maternal uniparental disomy (UPD) of chromosome 15; (D) the remaining reliably diagnoses of 7 PWS and 3 AS cases showed abnormal methylation patterns of 15q11-q13 chromosome, but none of the alterations shown by the above groups, although they may have harbored deletions undetected by the markers used. This study highlights the importance of using a combination of cytogenetic and molecular tests for a reliable diagnosis of PWS or AS, and for the identification of genetic alterations.
Adolescent↗
Limits of clinical assessment in the accurate diagnosis of Machado-Joseph disease.
BACKGROUND: Machado-Joseph disease (MJD) is a type of autosomal dominant spinocerebellar ataxia for which molecular diagnosis is available. We identified 4 families segregating the MJD mutation in which no unequivocal clinical diagnosis could be established prior to molecular testing. Ethnic background, clinical, and molecular characteristics of 19 individuals carrying the MJD mutation in these 4 families were compared with a group of 32 Portuguese families who were clinically diagnosed as having MJD and were found to carry the MJD mutation. RESULTS: Several factors seemed to have an impact in the accuracy of the clinical diagnosis, such as ethnic origin; the number of affected individuals available for examination in each family; the absence of patients showing specific clinical features, such as extrapyramidal signs; and the size of the expanded CAG repeat in the MJD gene. CONCLUSION: Since the recognition of MJD based solely on clinical grounds might sometimes be misleading, a search for the MJD mutation should be performed in patients with a clinical diagnosis of spinocerebellar degeneration.
Adult↗
Chlamydia/gonorrhea combo and HR HPV DNA testing in liquid-based pap.
Residual material from liquid-based pap (LBP) test has been used for molecular testing of Human Papilloma Virus (HR HPV) DNA. LBP test specimens (1,025) were evaluated to determine how often residual material was insufficient to perform microbiological testing. The specimens were tested for Chlamydia trachomatis and Neisseria gonorrhea (CCGT) alone and in combination with HR HPV(CCGT + HR HPV), using PCR method and HYBRID CAPTURE 2, respectively. A minimum volume of 5 ml (CCGT: 0.5-1 ml, HPV: 4 ml) of residual material is required for both the tests. The residual material was measured at >5 ml, < or =5 ml, and 0.5 ml volumes and documented. Results were tabulated. The insufficient rate for cases submitted for CCGT was 0.2% and 7.6% for HR HPV, with a detection rate of 40.9% for HR HPV. Utilizing residual material from LBP test for microbiological testing, as well as DNA testing for HR HPV is a convenient, cost-effective means to enhance patient care.
Animals↗
Anthelmintic resistance: past, present and future.
Anthelmintic resistance continues to increase in geographic range, in the number of species affected and the range of drugs involved. Several aspects of resistance have emerged as important issues. They include lack of genetic reversion, presence of side resistance and lack of universality. Furthermore, resistant isolates recovered from the field may have different characteristics to those selected in pen passage. Research into anthelmintic resistance has not progressed far beyond the stage of descriptive research. Some progress has been made in developing control strategies and in diagnosing resistance, especially in the development and adoption of in-vitro tests. However, these still need improvements in their ability to detect resistance to closantel and avermectin/milbemycin anthelmintics. Less progress into understanding the basis of resistance has occurred. Research priorities include improvement of diagnostic tests and the development of molecular tests, particularly for resistance to levamisole and the avermectin/milbemycins. Resistance itself, as a selectable marker for genetic transfection in parasites, is a potential tool for investigating parasite biology.
Animals↗
Molecular variability of the adhesin-encoding gene pvpA among Mycoplasma gallisepticum strains and its application in diagnosis.
Mycoplasma gallisepticum is an important pathogen of chickens and turkeys that causes considerable economic losses to the poultry industry worldwide. The reemergence of M. gallisepticum outbreaks among poultry, the increased use of live M. gallisepticum vaccines, and the detection of M. gallisepticum in game and free-flying song birds has strengthened the need for molecular diagnostic and strain differentiation tests. Molecular techniques, including restriction fragment length polymorphism of genomic DNA (RFLP) and PCR-based random amplification of polymorphic DNA (RAPD), have already been utilized as powerful tools to detect intraspecies variation. However, certain intrinsic drawbacks constrain the application of these methods. The main goal of this study was to determine the feasibility of using an M. gallisepticum-specific gene encoding a phase-variable putative adhesin protein (PvpA) as the target for molecular typing. This was accomplished using a pvpA PCR-RFLP assay. Size variations among PCR products and nucleotide divergence of the C-terminus-encoding region of the pvpA gene were the basis for strain differentiation. This method can be used for rapid differentiation of vaccine strains from field isolates by amplification directly from clinical samples without the need for isolation by culture. Moreover, molecular epidemiology of M. gallisepticum outbreaks can be performed using RFLP and/or sequence analysis of the pvpA gene.
Adhesins, Bacterial↗
Italian guidelines for molecular analysis in myotonic dystrophies.
Myotonic dystrophies, the most common form of adult muscular dystrophy, comprise at least two forms, clinically and genetically heterogeneous. Myotonic dystrophy type 1 and type 2 are both caused by unstable repetitions in untranslated gene regions: a [CTG]n expansion in the 3' region of the DMPK gene on chromosome 19q13 (DM1) and [CCTG]n tetranucleotide repeat located in the first intron of the ZNF9 gene on chromosome 3q21 (DM2). DM clinical features are caused by a gain of functions RNA mechanism in which the CUG and CCUG repeats alter nuclear functions, including alternative splicing of shared genes. Southern blot and/or polymerase chain reaction PCR-based approaches allow the detection of DM mutations in almost 100% of cases, however, the expansion size and the elevated grade of somatic instability make molecular testing for DM a diagnostic challenge. The increased use of DNA testing for DM generates many questions regarding the indications and interpretations of the test which require standardized methods, routinely available in molecular genetic laboratories. Here, we propose Guidelines for the molecular diagnosis of DM1 and DM2 approved by the Italian Ministry of Health in 2005 (Piano Nazionale Linee Guida, PNLG). Best practice for DM molecular analysis in diagnostic application, presymptomatic and prenatal testing, using direct and indirect approaches are described, with particular attention focused on ethical, legal and social issues. Overviews of materials used in the molecular diagnosis, as well as internet resources, are also included.
Genetic Testing↗
Clinical epidemiological quality in molecular genetic research: the need for methodological standards.
CONTEXT: A genetic basis has been identified for many medical conditions and some molecular tests have been commercialized. However, little attention has been given to the quality of clinical epidemiology in molecular studies. OBJECTIVE: To examine the clinical epidemiological quality of recent publications on molecular genetic analysis. DESIGN: Cross-sectional study of original research articles published in 1995, identified by manually searching 4 general clinical journals. Of 83 articles identified, 40 were selected for analysis; these 40 discussed molecular genetic techniques, studied 10 or more patients, and had inferential conclusions. MAIN OUTCOME MEASURE: Compliance of the selected articles with 7 methodological standards for clinical epidemiological science (reproducibility, objectivity, delineation of case group, adequacy of spectrum in case group, delineation of comparison group, adequacy of comparison group, and quantitative summary of results). RESULTS: Among the 40 inferential articles that studied 10 or more patients, only 5 (12.5%) complied with all 7 applicable standards, and 10 (25.0%) complied with all but 1 standard, whereas 25 articles (62.5%) failed to comply with 2 or more standards and 9 (22.5%) failed 4 or 5 standards. Most articles did not comply with standards for reproducibility (n = 25, 62.5%) or objectivity (n = 27, 67.5%); however, the majority of articles did comply with standards for adequacy of case group (n = 35, 87.5 %), adequacy of comparison group (n = 35, 87.5%), and quantitative summary of results (n = 36, 90%). CONCLUSIONS: Despite major laboratory advances in molecular genetic analysis, our data suggest that reported applications in clinical journals often have troubling omissions, deficiencies, and lack of attention to the different, but necessary, principles of clinical epidemiological science. Without suitable attention to fundamental methodological standards, the expected benefits of molecular genetic testing may not be achieved.
Clinical Medicine↗
Molecular detection of rifampin and ofloxacin resistance for patients who experience relapse of multibacillary leprosy.
Molecular detection of rifampin resistance (rpoB analysis) in Mycobacterium leprae was determined for 49 patients who experienced relapse of multibacillary leprosy and for 34 untreated patients. Molecular detection of ofloxacin resistance (gyrA analysis) was determined for the 12 patients who experienced relapse and who had received ofloxacin. Results of molecular tests were compared with the reference susceptibility test in the mouse footpad. Overall, the efficiency of molecular detection--that is, positive DNA amplification--was 95%, whereas that of the in vivo test was 55% (P<.001). Results of molecular detection and in vivo test were fully concordant when both were available--that is, for 35 rifampin--sensitive cases of leprosy (no rpoB mutation), 4 ofloxacin-sensitive cases (no gyrA mutation), 11 rifampin-resistant cases (rpoB missense mutations), and 1 ofloxacin-resistant case (gyrA mutation). rpoB and gyrA analysis appears to be an effective method for detection of rifampin and ofloxacin resistance in patients with leprosy.
Adult↗