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 253 records · Page 14Linked to original sources
PubMed2001

Preonset studies of spondyloepiphyseal dysplasia tarda caused by a novel 2-base pair deletion in SEDL encoding sedlin.

Spondyloepiphyseal dysplasia tarda (SEDT), an X-linked recessive skeletal disorder, presents with disproportionate short stature and "barrel-chest" deformity in affected (hemizygous) adolescent boys. In four reported families to date, mutations in a gene designated SEDL (spondyloepiphyseal dysplasia late) cosegregate with SEDT. We diagnosed SEDT in a short-stature, kyphotic 15-year-old boy because of his characteristic vertebral malformations. Clinical manifestations of SEDT were evident in at least four previous generations. A novel 2-base pair (bp) deletion in exon 5 of SEDL was found in the propositus by polymerase chain reaction (PCR) amplification and sequencing of all four coding exons. The mutation ATdel241-242 cosegregated with the kindred's skeletal disease. The deletion is adjacent to a noncanonical splice site for exon 5 but does not alter splicing. Instead, it deletes 2 bp from the coding sequence, causing a frameshift. A maternal aunt and her three young sons were investigated subsequently. Radiographs showed subtle shaping abnormalities of her pelvis and knees, suggesting heterozygosity. X-rays of the spine and pelvis of her 8-year-old son revealed characteristic changes of SEDT, but her younger sons (aged 6 years and 3 years) showed no abnormalities. SEDL analysis confirmed that she and only her eldest boy had the 2-bp deletion. Molecular testing of SEDL enables carrier detection and definitive diagnosis before clinical or radiographic expression of SEDT. Although there is no specific treatment for SEDT, preexpression molecular testing of SEDL could be helpful if avoiding physical activities potentially injurious to the spine and the joints proves beneficial.

Adolescent↗
PubMed1999

Colon cancer testing and screening.

Laboratory testing has the potential to favorably affect the outcome of patients with neoplasia by applications in screening, risk identification, surveillance, diagnosis, prognosis, prediction of tumor response or resistance to therapies, and prediction of toxic effects from therapies. Molecular testing directed at colorectal neoplasia is currently in use for diagnosis and characterization of rare, highly penetrant inherited syndromes due to germline mutation of the APC suppressor gene or DNA nucleotide mismatch repair genes. Routine application of molecular assays of colorectal tumors as prognostic and predictive markers is likely to occur in the near future, but major advances in technology are needed to begin to move molecular testing into screening of the general population and surveillance of subjects at increased risk. It seems certain that molecular methods will become increasingly important in improving the outcome of patients with colorectal neoplasia and in contributing to continued decline of the death rate from this common cancer.

Biomarkers, Tumor↗
PubMed2026

Prevalence of homologous recombination repair genes alterations in metastatic castration-resistant prostate cancer, a multicentric study.

INTRODUCTION: Homologous Recombination Repair (HRR) genes alterations are a resistance mechanism to therapies by taxanes or Androgen Receptor Signalling inhibitors in Metastatic Castration Resistant Prostate Cancer (mCRPC). BRCA-mutated mCRPC patients are eligible to poly adenosine diphosphateribose polymerase inhibitors (PARPi). Therefore, assessing the population-specific prevalence of HRR-related genes alterations is of public healthcare importance. METHODS: This retrospective, non-interventional, multicentric study was conducted across 6 reference French centers in a "real-life" setting. 788 paraffin-embedded mCRPC patient-samples were included and submitted to testing for BRCA1/2 in six different centers; additionally, non-BRCA HRR-related genes were investigated in two different centers. RESULTS: Among the samples, n=602 (76.4%) were contributive for molecular testing. In multivariate analysis by logistic regression and sensitivity analysis, only sample age (P<0.01), sample surface area (P=0.02) and institution (P=0.018) remained statistically significant. BRCA alterations were detected in n=39/602 (6.5%) of contributive samples, with n=35 and n=4 alterations of BRCA2 and BRCA1 respectively. Non-BRCA HRR-related genes alterations were detected in n=12/157 (7.6%) of contributive samples, with alterations of mainly ATM (n=6, 3.8%), CDK12 (n=4, 2.5%) and CHEK2 (n=2, 1.3%). DISCUSSION: In this study, testing contributivity was similar or higher that of other studies in the literature, and observed mutations prevalences were similar to that of other screenings of western populations. Harmonising per-centres protocols and enhancing molecular testing contributivity with the screening of circulating DNA samples and expanding its range by including non-BRCA HRR-related genes in all reference centres will enable more patients to be accurately treated by targeted therapies. LEVEL OF EVIDENCE: 3 (grade C).

Male↗
PubMed2005

Light scattered by model phantom bacteria reveals molecular interactions at their surface.

Testing molecular interactions is an ubiquitous need in modern biology and molecular medicine. Here, we present a qualitative and quantitative method rooted in the basic properties of the scattering of light, enabling detailed measurement of ligand-receptor interactions occurring on the surface of colloids. The key factor is the use of receptor-coated nanospheres matched in refractive index with water and therefore optically undetectable ("phantom") when not involved in adhesion processes. At the occurrence of ligand binding at the receptor sites, optically unmatched material adsorbs on the nanoparticle surface, giving rise to an increment in their scattering cross section up to a maximum corresponding to saturated binding sites. The analysis of the scattering growth pattern enables extracting the binding affinity. This label-free method has been assessed through the determination of the binding constant of the antibiotic vancomycin with the tripeptide l-Lys-d-Ala-d-Ala and of the vancomycin dimerization constant. We shed light on the role of chelate effect and molecular hindrance in the activity of this glycopeptide.

Bacteria↗
PubMed2001

Frequency of rpoB mutations inside and outside the cluster I region in rifampin-resistant clinical Mycobacterium tuberculosis isolates.

The prevalence of recently described mutation V176F, located in the beginning of the rpoB gene and associated with rifampin resistance and the wild-type cluster I sequence, was determined by analyzing the distribution of rpoB mutations among 80 rifampin (RIF)-resistant Mycobacterium tuberculosis strains isolated in Germany during 1997. The most frequent rpoB mutations were changes in codon 456 (52 isolates, 65%), followed by changes in codon 441 (13 isolates, 16%) and codon 451 (11 isolates, 14%). The V176F mutation was detected in one isolate of the study population and in 5 of 18 RIF-resistant strains with no cluster I mutation from six previously published studies. In three isolates, a mixture of resistant and susceptible subpopulations (heteroresistance) prohibited the detection of rpoB mutations in the initial analysis; however, in these isolates, cluster I mutations could be verified after a passage on RIF-containing medium. IS6110 DNA fingerprinting of 76 strains revealed eight clusters comprising 27 strains with identical restriction fragment length polymorphism patterns that mainly also show identical rpoB mutations and identical or similar drug resistance patterns. In conclusion, our results indicate that the V176F mutation should be included in molecular tests for prediction of RIF resistance in M. tuberculosis. We further demonstrated that heteroresistance caused by a mixture of mycobacterial subpopulations with different susceptibilities to RIF may influence the sensitivity of molecular tests for detection of resistance.

Adult↗
PubMed2001

Characterization of an undifferentiated malignancy as a mast cell tumor using mutation analysis in the proto-oncogene c-KIT.

A 6.5-year-old female Boxer was euthanized and presented for necropsy following rapid clinical decline concomitant with the development of numerous tumor masses. The largest of these masses was in the same location as a mast cell tumor that had been previously removed from this dog. Gross examination revealed the presence of nodules 5-200 mm in diameter throughout the body, including the lymph nodes. Histologic analysis showed an influx of round cells with no granules, leading to the provisional diagnosis of systemic lymphosarcoma. Immunohistochemical staining for B- and T-lymphocyte antigens was negative. Molecular tests were used to identify a tandem duplication in the c-KIT proto-oncogene from both the earlier mast cell tumor and the current nodules, implicating a common origin. Addition of molecular testing to conventional necropsy evaluations allowed a definitive diagnosis of mast cell tumors.

Animals↗
PubMedDate not supplied

[Prospects for genetic hearing loss screening: 35delG mutation tracking in a newborn population].

OBJECTIVES: To investigate the prevalence of the 35delG mutation in a newborn population, with specific molecular testing, and to evaluate the prospects for genetic neonatal screening for hearing impairment. POPULATION AND METHOD: 233 newborn were evaluated at the Hospital de Base de São José do Rio Preto, SP, for molecular analysis of the 35delG mutation in the connexin 26 gene, with the reaction technique in allele-specific polymerase chain reaction, after genomic DNA extraction from umbilical cord blood. RESULTS: Five heterozygotes were identified, obtaining a prevalence of 2.24% of 35delG mutation carriers in the study population. CONCLUSION: Using the molecular test allowed for the identification of the 35delG mutation in the study population with the possibility of being used as a complement to neonatal audiometric screening as being simple, fast, and easily to perform with low costs.

Brazil↗
PubMed2006

Amniocentesis results: investigation of anxiety. The ARIA trial.

OBJECTIVES: The Amniocentesis Results: Investigation of Anxiety (ARIA) trial tested two hypotheses: first, that giving amniocentesis results out on a fixed date alters maternal anxiety during the waiting period, compared with a policy of telling parents that the result will be issued 'when available' (i.e. a variable date), and secondly, that issuing early results from a rapid molecular test alters maternal anxiety during the waiting period, compared with not receiving any results prior to the karyotype. The effects of the two interventions on anxiety 1 month after receiving karyotype results were also examined. DESIGN: A multi-centre, randomised, controlled, open fixed sample, 2 x 2 factorial design trial, with equal randomisation. SETTING: Twelve hospitals in England offering amniocentesis as a diagnostic test for Down's syndrome. PARTICIPANTS: A total of 226 women who had had an amniocentesis were randomised between June 2002 and July 2004. Eight women with abnormal results or test failure were excluded post-randomisation. INTERVENTIONS: Issuing karyotype results on a prespecified fixed date, rather than issuing them as soon as they became available and issuing karyotype results alone, or subsequent to issuing results from a rapid molecular test for the most common chromosomal abnormalities. MAIN OUTCOME MEASURES: Average anxiety during the waiting period, calculated using daily scores from the short version of the Spielberger State-Trait Anxiety Inventory (STAI). Recalled anxiety, measured 1 month after receiving karyotype results, using a rating scale. Anxiety at the 1-month follow-up, measured using the short-form STAI. RESULTS: There was no evidence that giving out karyotype results on a fixed or on a variable date altered maternal anxiety during the waiting period. However, the analysis only had sufficient power to detect a moderate to large effect. Issuing early results from a partial, but rapid, test reduced maternal anxiety during the waiting period, compared with receiving only the full karyotype results. This was a moderate to large effect. In addition, group differences in recalled anxiety reflected fairly closely the differences in anxiety women had experienced while waiting for results. One month after receiving normal karyotype results, anxiety was low in all groups, but women who had been given rapid test results were more anxious than those who had not. This was a small to moderate effect. CONCLUSIONS: Since there are no clear advantages in anxiety terms of issuing karyotype results as soon as they become available, or on a fixed date, women could be given a choice between them. Rapid testing was a beneficial addition to karyotyping, at least in the short term. This does not necessarily imply that early results would be preferred to comprehensive ones if women had to choose between them. There should be further research, including more qualitative studies, into the causes, characteristics and consequences of anxiety associated with prenatal testing. The effects of different testing regimes on short- and long-term anxiety, on the preferences of women and on the relationship between anxiety and preference should be investigated. More research is needed on the ways in which information might be used to minimise anxiety in different testing regimes. Further research is also required into the policy implications of incorporating individual preferences for different testing regimes into prenatal testing programmes.

Adult↗
PubMed2000

Phenotypic manifestations associated with CAG-repeat expansion in the androgen receptor gene in male patients and heterozygous females: a clinical and molecular study of 30 families.

Spinal and bulbar muscular atrophy (Kennedy disease) is an adult form of X-linked motor neuron disease caused by the expansion of a polymorphic CAG-repeat sequence in the first exon of the androgen receptor gene. We studied clinical and molecular features of 36 patients and 19 heterozygous females. Phenotypic manifestations and disease severity broadly varied among our spinal and bulbar muscular atrophy patients. The size of CAG expansion significantly influences the age of disease onset, but neither clinical features nor disease severity. The majority of carrier women presented signs of chronic denervation at neurophysiological examination and, in three cases, low-amplitude sensory action potentials were recorded. Notably, a few women developed mild signs of bulbar motor neuron impairment later in life. The identification of a large number of patients by the use of the molecular test further supports the hypothesis that Kennedy disease had been previously underdiagnosed, probably because of the great variability of clinical presentation. Although an early diagnosis may not be crucial for treatment, given the lack of effective therapy, the molecular testing can be of great relevance for disease prognosis and genetic counseling.

Action Potentials↗
PubMed1994

Newborn screening for cystic fibrosis in Wisconsin: first application of population-based molecular genetics testing.

Infants born in Wisconsin are being screened for cystic fibrosis (CF) associated with the F508 mutation. This screening program has been developed during 9 years of research supported by the National Institutes of Health and involves a unique, two-tier system employing measurement of immunoreactive trypsinogen (IRT) initially. When the IRT level is high, DNA is extracted from the neonatal dried blood specimen and analyzed for the F508 mutant allele, following polymerase chain reaction (PCR) amplification; the F508 mutation is present in more than 90% of CF patients and accounts for the common, severe form of the disease. Infants with a positive DNA test are either CF heterozygote carriers or CF patients, depending on the results of a sweat test, which should be performed at 4 weeks of age. Screening the newborn population for CF provides the opportunity for early nutritional and respiratory interventions, as well as genetic counseling. This represents the first population-based application of molecular genetics for detection of a major congenital disorder causing serious public health problems. The process by which the recommendation was reached to screen for CF is described in this article, along with new information on the pathogenesis of CF, its clinical presentation, the rationale for newborn screening, and the method developed for the screening program.

Cystic Fibrosis↗
PubMed1988

Secondary structural analyses of the nicotinic acetylcholine receptor as a test of molecular models.

Circular dichroism (CD) spectroscopy was used to determine that the secondary structure of purified nicotinic acetylcholine receptor (AChR) of Torpedo californica in both reconstituted vesicles and a cholate-solubilized state is, on average, 23% alpha-helix, 43% beta-sheet, 6% beta-turn, and 28% random coil. These data can serve to test models by placing limits on the particular types of secondary structural motifs which make up the receptor. A number of models proposed for the AChR are discussed in relation to the experimental data presented. Additionally, the protein in both vesicle and solubilized environments was exposed to an agonist, carbamylcholine, or a competitive antagonist, hexamethonium, to monitor net conformational changes upon ligand binding. The protein secondary structure was not changed upon solubilization, nor was any large net conformational change observed upon ligand binding, although small local or compensatory changes cannot be ruled out.

Animals↗
PubMed2006

[Vascular Ehlers-Danlos syndromes--biochemical and molecular-genetic investigations].

INTRODUCTION: The Ehlers-Danlos syndromes (EDS) are a heterogeneous group of heritable connective tissue disorders characterised by joint hypermobility, involvement of skin and tissue fragility. The Villefranche criteria have simplified its diagnosis, which, however, remains difficult in children and young adults with vascular and hypermobile EDS as well as in patients without a positive family history. Diagnosis of vascular EDS is important for clinical follow-up, genetic counseling and prenatal diagnosis. We describe the biochemical and molecular-genetic diagnosis of vascular EDS. MATERIALS AND METHODS: We describe five families with vascular EDS. Analysis of (pro)collagens obtained from cultured fibroblasts was done using SDS-PAGE. The structure and amounts of (pro)collagen I, III and V were determined by autoradioflourography. This was also done in 362 controls or patients without a diagnosis of vascular EDS. Molecular testing was done in Professor Anne de Paepe's laboratory in Belgium by sequencing of COL3A1. RESULTS: (Pro)collagen from all five patients with vascular EDS was abnormal by SDS-PAGE: intracellular retention, reduced secretion and overmodification of the a1 chains of (pro)collagen III. Molecular analysis revealed an abnormality of COL3A1 in all patients. Abnormalities of (pro)collagen III were not observed in patients without a diagnosis of vascular EDS. Among 90 patients with non-vascular EDS, one patient had an abnormality of collagen I. DISCUSSION: Biochemical analysis of (pro)collagen obtained from cultured fibroblasts is a good screening procedure for vascular EDS, but it is of limited value in non-vascular EDS. Molecular testing will disclose an abnormality of COL3A1 in many patients with abnormal (pro)collagen III on SDS-PAGE. The findings make precise genetic counselling and prenatal diagnosis possible in families with vascular EDS.

Adult↗
PubMed1996

Clinical and histopathological features of abnormalities of the dystrophin-based membrane cytoskeleton.

The majority (approximately 70%) of cases of childhood and adult onset muscular dystrophies in males, and approximately 10% of dystrophy in girls and women, show underlying primary abnormalities of dystrophin. Approximately 2% of childhood/adult onset muscular dystrophy patients have a primary defect of one of the three sarcoglycan proteins identified to date (alpha, beta, gamma). The finding of a sarcoglycan deficiency in muscle generally does not reflect the primary underlying defect, and thus testing of biopsies for sarcoglycans should be used only after normal dystrophin findings, and in conjunction with gene mutation testing. Approximately 30% of neonatal onset congenital muscular dystrophy has been shown to be due alpha 2-laminin (merosin) deficiency. alpha 2-laminin is a component of the myofiber basal lamina, and this protein interacts with the dystrophin-based membrane cytoskeleton. Due to the similar clinical and histopathological features of the different etiologies of muscular dystrophies, molecular testing of peripheral blood DNA and muscle biopsy protein are a critical part of the clinical work-up of dystrophy patients. Many patients carrying a Becker dystrophy or limb-girdle dystrophy diagnosis should be re-evaluated with molecular tests to provide accurate genetic counseling to their families.

Cytoskeleton↗