PubMed Health⌕ Search

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.

At least 37 records · Page 2Linked to original sources
PubMed2002

Molecular testing for antibiotic resistance in Helicobacter pylori.

An estimated 7.5 million individuals in England and Wales are actively infected with Helicobacter pylori and hence knowledge of local resistance rates is of growing importance. Also, information on strain resistance following treatment failure is crucial in selecting an appropriate regimen as the development of bacterial resistance to antibiotics makes retreatment difficult. Molecular test methods may have an impact on improving the availability and accuracy of information on H pylori antimicrobial resistance to guide in the selection of primary as well as secondary backup treatment regimens.

Anti-Bacterial Agents↗
PubMed1999

P53 genotyping - an effective concept for molecular testing of head and neck cancer?

P53 mutations are currently recognized as the most common genetic alteration in human tumors. The purpose of our study was to evaluate the significance and reliability of p53 genotyping in head and neck cancer as a possible marker permitting the prediction of tumor behavior and clinical outcome. P53 genotyping in our study refers to highly sensitive molecular screening in order to detect structural alterations in the nucleic acid sequence of the gene. Exons 2-11 and adjacent intronic regions were screened for mutations by direct genomic sequencing or by bi-directional dideoxyfingerprinting in 66 primary tumors of the larynx, pharynx and oral cavity. Alterations in the of the p53 gene were detected in 36% (24 of 66) of the analyzed tumors, no mutation was found in our cohort outside exons 5-8. The frequency of p53 mutation had no correlation to the tumor stage or tumor site. The recurrence rate in patients with a p53 alteration was not significantly higher compared to patients without a p53 mutation in their primary tumors. Summarizing the results of our study only limited reliability of p53 genotyping as an effective concept for molecular testing of head and neck cancer was found.

Biomarkers, Tumor↗
PubMed1999

The genetics of Alzheimer disease and the application of molecular tests.

Two general classes of genes are associated with the development of Alzheimer disease (AD). The first group consists of genes that appear to cause AD when mutated, and the second category is composed of genes that are statistically associated with AD, depending on the inheritance of specific alleles. This paper reviews the current state of knowledge about the genetics of AD, and we then discuss the two molecular tests that are currently commercially available. These include a genetic test for mutations in the presenilin 1 (PS1) gene that can diagnose or predict a subset of early onset familial AD with a high degree of certainty. The value of the genetic test for the apolipoprotein (APOE) allele status is far less clear. Inheritance of the epsilon 4 allele is associated with an increased risk of AD at a population level, but APOE genotyping is inappropriate for prediction of future disease in an individual and offers only a marginal increase in diagnostic certainty when symptomatic individuals are tested. In the future, genetic tests may become more broadly applicable to the diagnosis and prediction of AD. However, the utility of such tests is currently limited to a small subset of individuals because in the vast majority of AD cases no clear genetic or environmental cause has been defined.

Alzheimer Disease↗
PubMed1999

Usefulness of molecular testing in Huntington's disease.

BACKGROUND: Uncertainty in diagnosing Huntington's disease (HD) may occur in the absence of a family history or typical movement disorders. HD is characterized by a progressive disturbance of typical movement disorders (i.e., chorea, athetosis), psychiatric symptoms (i.e., depression, insomnia, anxiety, suspiciousness), and cognitive deterioration, in the absence of a dominant family history of similar disorders. Often, some of these symptoms are missing, which makes the diagnosis difficult. In recent years molecular testing has become the gold standard for diagnosing HD. Diagnostic accuracy for HD on genetic screening of patients and their families is important. We evaluated a polymerase chain reaction (PCR) technique for the detection of CAG trinucleotide repeats in the Huntington IT15 gene on chromosome 4 for the diagnosis of HD. METHODS: A segment of the Huntington gene was amplified by PCR using the primers HD-1 and HD-3 flanking the CAG repeat sequence. Genomic PCR was performed on DNA extracted from the peripheral leukocytes of 12 patients from three unrelated families. One family had no documented history of movement or mental disorders, while the other two did. These two, therefore, required pre-symptomatic testing and exclusion of diagnosis in a seemingly symptomatic case. RESULTS: We successfully identified four subjects with expansion of CAG trinucleotide repeats in Huntington gene IT15 on chromosome 4. Movement disorder was present in three of these subjects. One was the sister of subject 4, who was asymptomatic. A sister of subject 9 was ruled out from having HD by PCR despite having depression symptoms, which are frequently seen in HD patients. CONCLUSIONS: Genetic testing is of prime importance in the establishment of an accurate diagnosis of Huntington's disease, especially in "sporadic" cases and presymptomatic family members, and for the exclusion of HD in family members with equivocal symptoms.

Adult↗
PubMed2005

[Application of the molecular test PCR multiplex for identification of Mycobacterium bovis BCG strains].

In our last paper (18) we described the problem of proper microbiological identification of BCG strains and how important is distinguishing vaccine strain from virulent strains of Mycobacterium tuberculosis complex. We have suggested the modern algorithm of BCG strains identification including mycolic acids profile by HPLC and 14C PZA resistance methods. These methods allowed us to made fast and accurate microbiological identification of side effects of BCG vaccine in the children. Identification of BCG by HPLC is possible within one working day compared with 3-4 weeks required for conventional methods. However both methods need very expensive instruments like HPLC and/or Bactec-460 Tb radiometric system. Presently we have evaluated molecular test based on the analyzis of the region RD1 encoding a 9.5-kb fragment. This fragment is deleted in all BCG substrains (6) and present in all human and bovine virulent strains. To evaluate this method for the rapid and specific detection of BCG, a large strain collection (32 strains) representating M. bovis BCG (vaccine strains and strains isolated from the children in case of adverse reactions after vaccination) M. bovis and M. tuberculosis from own collection was analyzed. RD1 was present in all 15 M. tuberculosis and M. bovis tested strains and deleted in 17 of 18 BCG strains. The multiplex PCR method was 100% sensitive and specific for the identification of BCG among strains of the Mycobacterium tuberculosis complex. Multiplex PCR can be used as a diagnostic test and has significant advantages over existing methods.

Animals↗
PubMed2005

Preliminary evaluation of a cervical self-sampling device with liquid-based cytology and multiparameter molecular testing.

OBJECTIVE: To compare the collection of a liquid-based cell sample using a cervical self-sampling device and traditional sampling using cytologic and molecular-based tests. STUDY DESIGN: This study evaluated the sampling efficiency of the Fournier Cervical Self-Sampling Device (BPG, LLC, Miami, Florida) with regard to overall cell volume of the sample, cytologic diagnoses Path, TriPath Imaging, Burlington, North Carolina) and molecular-based tests for Chlamydia, Gonorrhoeae and human papillomavirus (Hybrid Capture 2, Digene Corp., Gaithersburg, Maryland). Paired samples were blinded and prepared using the SurePath method. RESULTS: The self-collected samples showed an overall increase in cellularity when compared to the cellularity of samples obtained from traditional sampling. Cytologic results were comparable for the 2 sampling methods. The self-sampling device showed greater sensitivity with regard to molecular-based human papillomavirus testing. CONCLUSION: The Fournier Device shows promise in the area of cytology and molecular diagnostics. The ability to perform cytology and molecular-based assays using a single sample obtained directly by the patient can lower the costs of screening and provide an efficient method of screening women in resource-poor countries or when cultural barriers exist to the use of traditional sampling methods.

Adult↗
PubMed2005

Molecular testing for microsatellite instability and its value in tumor characterization.

Molecular analysis of tumor tissue has become a rapidly expanding field in medical research, exploiting the advantages of new technologies adapted to high-throughput examination of genetic alterations, gene and protein expression patterns. Only exceptionally, these approaches have found their way into routine clinical diagnosis and therapy. Microsatellite instability testing has been established as a very powerful tool to identify patients with hereditary nonpolyposis colorectal cancer, one of the most common familial cancer syndromes. In addition, there is emerging evidence that microsatellite instability analysis may become increasingly important for the clinician, having considerable impact on patients' prognosis as well as therapeutic decisions, at least in colorectal cancer patients. A better understanding of the microsatellite instability phenotype, its pathogenesis and implications for the course of the disease will pave the way for novel diagnostic and therapeutic strategies specifically tailored to microsatellite-unstable tumors. This review summarizes the current significance of molecular testing for microsatellite instability in several tumor entities and provides prospects of future developments.

Animals↗
PubMed2001

Highly polymorphic short tandem repeat analyses clarify complex molecular test results.

Judicious application of highly polymorphic short tandem repeat (STR) analyses and modification of assay conditions readily distinguished nonparentage from true parentage, with occasional failure to transmit one parentally derived allele. These categories were resolved with a reliability of >99.9%, the standard applied to most DNA evidence presented in a U.S. court of law. While completing a single prenatal diagnosis submitted at 19 weeks gestation, the authors found that one polymorphic grandpaternal allele did not amplify, a duplicate control propositus' DNA sample had been switched by an outside laboratory, and recombination occurred in maternal meiosis within the mutant gene region. In two parentage cases with one available parent, a Y-linked STR or an autosomal STR was modified when transmitted to the offspring. In contrast, some apparently inconsistent results between parental DNA and offspring were resolved by purifying or diluting the original extracted DNA samples. Thus, the source of each complex molecular test result was characterized unambiguously by testing a sufficient number of highly polymorphic STR loci and by purifying or diluting troublesome DNA samples to diminish polymerase chain reaction amplification artifact.

Adult↗
PubMed1998

Microdissection-Based p53 Genotyping: Concepts for Molecular Testing.

p53 is the most commonly altered tumor-suppressor gene in humans, involved in the development and progression of many diverse forms of human cancer. Although much remains to be learned about the biology of this important growth regulatory gene, sufficient experience has been accumulated with respect to the occurrence and pattern of p53 mutational change to justify molecular diagnostic testing for specific objectives. The authors outline specific concepts for testing with particular emphasis for solid tumor molecular diagnostics. This article focuses on microdissection-based fixed tissue molecular analysis, introducing new considerations related to quality control appropriate for this type of methodology. Given the rapidly evolving nature of molecular genetics, the suggestions provided here should be viewed as flexible. Nevertheless, the concepts are intended to serve as a model for other oncogene/tumor suppressor-gene assays to be developed with the overall purpose of establishing informative integrated histopathologic/genetic molecular diagnostic testing to complement standard microscopic analysis.

Journal Article↗
PubMed2003

Should molecular testing be required for diagnosing synovial sarcoma? A prospective study of 204 cases.

BACKGROUND: The t(X;18) translocation is a specific marker of synovial sarcomas (SS). Detection of SYT-SSX transcripts by polymerase chain reaction (PCR) was tested on preselected specimens of well-established histologic types, but to our knowledge, the diagnostic utility of molecular assays on a series of potential SS in comparison with conventional tools has never been reported. METHODS: Two hundred four consecutive cases of potential SS submitted for a second opinion were studied prospectively. On the basis of clinical context, histologic aspect, and immunohistochemical profile, the tumors were divided into three categories: 1) diagnosis of SS certain, when the only possible diagnosis was SS; 2) diagnosis of SS probable, when SS was the first diagnosis contemplated, but a differential diagnostic issue was raised by other tumors; 3) diagnosis of SS possible, when the diagnosis of SS was not the first diagnosis considered. Detection of SYT-SSX transcripts was performed using real-time PCR from fixed, embedded tissue as a systematic test. RESULTS: Sufficient RNA samples were recovered for PCR from 177 specimens (87%). One hundred four specimens (51%) were positive for SYT-SSX transcripts. Tumor sites of SS included the extremities (n = 57), lung (n = 13), trunk wall (n = 12), head and neck (n = 6), and other sites (n = 16). There were 61 monophasic, 22 poorly differentiated, 17 biphasic, and 4 predominantly epithelial SS. For 58 tumor specimens (29%), diagnosis of SS was certain before molecular testing; 49 (84.5%) of these 58 contained SYT-SSX transcripts. For 39 tumor specimens (19%), diagnosis of SS was probable; 29 (74.4%) of these 39 contained SYT-SSX transcripts. For 107 tumor specimens (52%), diagnosis of SS was only possible and strongly challenged by another histologic type. The issue consisted mainly of making the distinction between an SS and a poorly differentiated spindle cell sarcoma (n = 49), a poorly differentiated round cell sarcoma (n = 34), a carcinoma (n = 11), a myoepithelioma (n = 8), or an epithelioid fibrosarcoma (n = 5).Twenty-six tumor specimens (24.3%) contained SYT-SSX transcripts-10, 7, 5, 3, and 1 in the spindle cell tumor, round cell tumor, carcinomalike tumor, myoepitheliomalike tumor, and epithelioid-fibrosarcoma-like tumor categories, respectively. CONCLUSIONS: Molecular testing was not required if the diagnosis of SS was certain or probable on the basis of clinical, histologic, and immunohistochemical evaluation. However, it proved to be very helpful or necessary when the diagnosis of SS was only possible and was challenged by other tumor types, mainly other spindle cell sarcomas, round cell sarcomas, carcinomas, myoepitheliomas, and epithelioid fibrosarcomas.

Adolescent↗
PubMed2003

Clinical applications of BCR-ABL molecular testing in acute leukemia.

Recent advances in molecular genetics impact the health care and outcome of patients with acute lymphoblastic leukemia (ALL). BCR-ABL, a common molecular defect in adult ALL, is a valuable tumor marker whose detection influences prognosis and clinical management decisions. Molecular methods such as fluorescence in situ hybridization (FISH), reverse-transcriptase polymerase chain reaction (rtPCR), and real-time quantitative rtPCR can be used to detect the chimeric BCR-ABL gene or its transcripts. These molecular assays improve our ability to measure residual disease and to estimate risk of relapse. On the horizon are gene expression profiles that will likely provide additional information beyond what is obtainable with current clinical and laboratory approaches.

Benzamides↗
PubMed2026

Chinese expert consensus on precision testing and molecular diagnosis of pancreatic cancer (2025).

This consensus by the CSCO Pancreatic Cancer Expert Committee establishes evidence-based guidelines for molecular testing in pancreatic ductal adenocarcinoma. It details recommendations for biomarkers (e.g., KRAS, BRCA, MSI), liquid biopsy, and precision imaging to direct targeted therapies and immunotherapy, aiming to standardize diagnosis and optimize individualized patient care. Pancreatic ductal adenocarcinoma (PDAC) is the most common pathological type of primary pancreatic malignancy, accounting for ~95% of cases and generally referred to as pancreatic cancer [1]. Its prognosis is extremely poor and its incidence continues to rise [2]. According to the most recent global cancer statistics, the incidence of pancreatic cancer ranks 12th among all cancers, and its mortality ranks 6th, making it one of the deadliest malignancies worldwide [3]. Approximately 57% of patients have metastatic disease at diagnosis and require systemic therapy, for which chemotherapy remains the standard first-line option [1]. However, the overall response rate to currently available systemic regimens is low, and the 5-year survival rate for patients with metastatic disease remains below 5% [3]. Although most pancreatic cancers harbor canonical driver mutations, they exhibit marked heterogeneity at the molecular level. Whole-genome sequencing (WGS) and integrative genomic analyses have identified molecular subtypes of PDAC with potential clinical relevance [4-9]. With the increasing implementation of precision oncology, the Chinese Society of Clinical Oncology (CSCO) Guidelines for the Diagnosis and Treatment of Pancreatic Cancer give a level 1 recommendation to perform genetic and other molecular testing on tissue or cytologic specimens as part of the pathological diagnostic work-up, in order to guide individualized treatment, including targeted therapy and immunotherapy [10]. To further promote the use of genetic and molecular testing in the precision treatment of pancreatic cancer, the CSCO Pancreatic Cancer Expert Committee convened a multidisciplinary panel to develop the present Chinese Expert Consensus on Precision Testing and Molecular Diagnosis of Pancreatic Cancer (2025), aiming to provide clinicians with an authoritative reference for precision diagnostics and treatment decision-making.

Humans↗
PubMedDate not supplied

Tissue microarrays for testing molecular biomarkers of cervical intraepithelial neoplasia: feasibility study.

OBJECTIVE: To test the possibility of creating tissue microarrays of pre-malignant lesions of the cervix. STUDY DESIGN Paraffin-embedded blocks of 240 cervical tissue specimens were sampled. Lesions from benign squamous and glandular epithelium through various grades of cervical intraepithelial neoplasia (CIN) to frank carcinoma of squamous and glandular origin were cored with a 0.6-mm needle and arrayed in 4 tissue blocks. Sections of these blocks were stained with hematoxylineosin (H-E) and evaluated as to adequacy of tissue cores, representativity of the material and correspondence to the original diagnosis. Immunohistochemical staining with p16 and a novel marker C4.8(4/2/#1) was performed. RESULTS: In > 80% of cases sufficient material from the lesion could be obtained. No or inadequate material was seen in 6% of cases. The core sample did not correspond to the original diagnosis in 12% of cases. The reason was mainly a discrepancy in the grade of the CIN. Discrepancies in diagnoses occurred in only premalignant lesions. Immunohistochemical staining could reliably be performed and evaluated on all tissue cores. CONCLUSION: Tissue microarrays of cervical intraepithelial lesions are technically feasible and can be created reliably. The key to success is a careful and repeated comparison of the tissue block with the corresponding H-E section. Tissue microarrays of preinvasive cervical lesions may allow high throughput analysis of emerging molecular biomarkers in cervical carcinogenesis.

Biomarkers↗
PubMed2003

Fecal multiple molecular tests to detect colorectal cancer in stool.

BACKGROUND & AIMS: Evaluation of molecular alterations in fecal DNA is a potential, noninvasive, alternative tool for the detection of colorectal cancer. We analyzed a large panel of molecular alterations involved in tumor transformation and progression to define their single diagnostic contribution in terms of sensitivity, cost, and time required to carry out the different tests. METHODS: DNA was analyzed in stool from 38 healthy individuals and in paired stools and primary lesions from 56 patients with colorectal cancer. p53 exons 5-8, K-ras exons 1-2, four fragments of adenomatous polyposis coli (APC) exon 15, and 5 microsatellite loci were analyzed. Moreover, DNA amplification was evaluated for 4 exons of both p53 and APC. RESULTS: K-ras (34%) and p53 (34%) mutations were the most frequent alterations in tumors, followed by microsatellite instability (13%) and APC mutations (13%). The most frequent event in stool was DNA amplification (51%), followed by alterations of K-ras (11%), p53 and microsatellite instability (6%), and APC (2%). K-ras and p53 gene mutations increased the capacity of DNA amplification to detect tumor cells by 8%. CONCLUSIONS: K-ras and p53 gene mutations were the most frequent alterations observed in stool from patients with colorectal cancer, but DNA amplification was even more frequent, being present in more than half of patients. If these preliminary results are confirmed in a prospective study on a larger case series, this approach could be used for noninvasive colon cancer diagnosis in screening programs.

Adult↗
PubMed1998

Characterization of MLH1 and MSH2 alternative splicing and its relevance to molecular testing of colorectal cancer susceptibility.

The phenomenon of alternative splicing in the DNA mismatch repair genes MLH1 and MSH2 was extensively investigated by coupled reverse transcription-polymerase chain reaction in different human tissues, including 42 mononuclear blood cell samples--31 obtained from familial colon cancer patients or their at-risk relatives and 11 from healthy blood donors--7 normal colonic mucosae, 4 established human cancer cell lines, 8 colorectal tumors, and one sample each of ileum, liver, muscle, thymus, breast, and EBV-transformed lymphoblasts. Several isoforms were observed for each gene. Products of MLH1 alternative splicing included mRNAs lacking alternative exons 6/9, 9, 9/10, 9/10/11, 10/11, 12, 16, and 17. For MSH2, products lacking exons 5, 13, 2 through 7, and 2 through 8 were identified. The levels of expression were found to vary among different samples. All isoforms were found in a relevant fraction (43-100%) of the mononuclear blood cell samples, as well as in other tissues. The splicing variants were also detected in normal colonic mucosa, with the exceptions of the MLH1 -6/9 and -10/11 and the MSH2 -13 isoforms. Germline mutations of MLH1 and MSH2 confer constitutional predisposition to the development of colorectal cancer and other neoplasms. A substantial proportion of the mutations identified so far involve alterations of the normal splicing process. Knowledge of the existence of multiple alternative splicing events, not caused by genomic DNA changes, is important for the evaluation of the results of molecular diagnostic tests based on RNA analysis.

Adaptor Proteins, Signal Transducing↗