Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Multiplex”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,711 records · Page 95Linked to original sources
PubMed2001

Identification of substrains of BCG vaccine using multiplex PCR.

Current methods for determining the identity of substrains of Mycobacterium bovis BCG (BCG) vaccine are labour intensive, or provide only limited substrain differentiation. In this paper we describe a multiplex PCR that distinguishes between M. tuberculosis (TB) and M. bovis and the non-pathogenic BCG strain, and also subdivides the BCG vaccine substrains investigated into seven distinct fingerprints based on six target regions in the DNA. This test is specific, rapid, reproducible and portable and is proposed as a novel test for BCG vaccine control. It offers substantial advantages over the methods currently in use. Using this test we have characterised a number of commercial BCG vaccines.

BCG Vaccine↗
PubMed1985

Arthrogryposis multiplex complex involving the temporomandibular joint.

A case of arthrogryposis multiplex complex involving the temporomandibular joints is reported. The anatomy and physiopathology of the arthrogrypotic articulation are reviewed. The role of biomechanical factors in the development and maintenance of joint surfaces is discussed. Treatment modalities are proposed.

Arthrogryposis↗
PubMed1996

Incidence of maxillofacial involvement in arthrogryposis multiplex congenita.

PURPOSE: This study determined the incidence of maxillofacial involvement in patients diagnosed with arthrogryposis multiplex congenita (AMC). PATIENTS AND METHODS: Twenty-three patients were evaluated by the pediatric physical medicine and rehabilitation, orthopedic surgery, and pediatric oral and maxillofacial surgery departments. Any patient in whom the diagnosis of AMC was in doubt was excluded from the study. All patients with limited mandibular function underwent computed tomography (CT) examination of their temporomandibular joints (TMJ). The results of physical therapy were followed. RESULTS: Five of the 23 patients diagnosed with AMC were found to have maxillofacial involvement, eg, presence of cleft palate, Robin-like sequence, high-arched palate, open-bite deformity, facial muscle weakness, esophageal dysfunction, and limited mandibular opening. No TMJ abnormalities were found by CT scan. Physical therapy was used for treatment of the limited opening, but relapse occurred quicky after therapy was discontinued. CONCLUSION: The incidence of maxillofacial findings is similar to that of most other reports. Treatment involves surgical correction of abnormal anatomy when possible (ie, cleft repair), symptomatic management (ie, esophageal dysfunction), and physical therapy.

Adolescent↗
PubMed2002

Multiplexed microsphere-based flow cytometric assays.

Flow cytometry has become an indispensable tool for clinical diagnostics and basic research. Although primarily designed for cellular analysis, flow cytometers can detect any particles in the lower micron range, including inert microspheres of different sizes, dyed with various fluorochromes. Over the past 20 years, microspheres have been used as calibrators for flow cytometers and also as a solid support for numerous molecular reactions quantitated by flow cytometry. Proteins, oligonucleotides, polysaccharides, lipids, or small peptides have been adsorbed or chemically coupled to the surface of microspheres to capture analytes that are subsequently measured by a fluorochrome-conjugated detection molecule. More recently, assays for similar analytes have been multiplexed, or analyzed in the same assay volume, by performing each reaction on a set of microspheres that are dyed to different fluorescent intensities and, therefore, are spectrally distinct. Some recent applications with fluorescent microspheres have included cytokine quantitation, single nucleotide polymorphism genotyping, phosphorylated protein detection, and characterization of the molecular interactions of nuclear receptors. The speed, sensitivity, and accuracy of flow cytometric detection of multiple binding events measured in the same small volume have the potential to replace many clinical diagnostic and research methods and deliver data on hundreds of analytes simultaneously.

Adsorption↗
PubMed2001

Sensory perineuritis presented as a mononeuritis multiplex associated with livedo vasculitis.

We report a 52-year-old patient affected by a mononeuritis multiplex and livedo vasculitis. Sural nerve biopsy showed mild thickening of the perineurium, vascular alterations with inflammatory cell infiltration in the perineurium, and remarkable loss of large and small myelinated fibers. A therapeutic trial of acetylsalicylic acid, danazol, and dipyridamole controlled the skin lesion without improvement of nerve conduction studies.

Anabolic Agents↗
PubMed2002

Multiplex PCR for simultaneous detection of 677 C-->T and 1298 A-->C polymorphisms in methylenetetrahydrofolate reductase gene for population studies of cancer risk.

Methylenetetrahydrofolate reductase (MTHFR) plays a pivotal role in folate metabolism by regulating the diversion of folate metabolites toward DNA methylation or toward DNA synthesis. Because aberrations in both of these pathways can be tumor promoting, the two common polymorphisms in the MTHFR gene, 677 C-->T and 1298 A-->C, have been implicated as risk factors for several cancers. Homozygosity for the 677 C-->T polymorphism and compound heterozygosity for 677 C-->T and 1298 A-->C polymorphisms both reduce enzyme activity by more than 50% and can promote oncogenic alterations in DNA methylation especially when folate status is low. Thus, rapid identification of both polymorphisms in MTHFR gene would be of importance in understanding the genetics of abnormal folate metabolism as related to human cancer risk. Here we describe a multiplex polymerse chain reaction/restriction fragment length polymorphism procedure in which two sets of primers are used to amplify simultaneously the DNA regions spanning 677 and 1298 loci in one PCR reaction. The amplified products are digested by HinfI or MboII followed by agarose gel electrophoresis for simultaneous detection of the 677 C-->T and 1298 A-->C polymorphisms in the same gel.

Base Sequence↗
PubMed1998

Detection of bcr/abl fusion transcripts by semiquantitative multiplex RT-PCR combined with a colormetric assay in Ph positive leukemia.

We studied the feasibility of the clinical application of a new bcr/abl analysis system, C-TRAK t(9;22), consisting of a multiplex RT-PCR and a colormetric assay. With this system, bcr/abl transcripts could be detected in all of 24 cytogenetic Philadelphia chromosome (Ph) positive leukemia patients and in none of eight Ph negative patients. Multiple bcr/abl transcripts could be detected in three of the 24 Ph positive patients, the fusion of bcr exon 1 to abl exon 2 (e1a2 junction) dominated that of bcr exon 13 to abl exon 2 (b2a2 junction) in two cases and that of bcr exon 14 to abl exon 2 (b3a2 junction) and b2a2 dominated e1a2 in one case. This system was sensitive enough to be able to detect even one bcr/abl transcript-producing cell in 50000 bcr/abl negative background cells, thus making it suitable for semiquantitative evaluation. Minimal residual disease (MRD) was monitored in one Ph positive leukemia patient who underwent allogenic bone marrow transplantation (allo-BMT). After allo-BMT, a weak positivity of the bcr/abl transcript continued with no clinical relapse; this result was consistent with that of a conventional nested PCR assay using ethidium bromide staining. Including all the procedures for RNA extraction, it took only about 10 h to detect the bcr/abl transcripts. Our findings indicate that this bcr/abl analysis system provides a quick and sensitive method for screening bcr/abl transcripts and possibly for monitoring MRD in Ph positive leukemia patients.

Acute Disease↗
PubMed1999

A multiplex-PCR/RFLP procedure for simultaneous CYP2E1, mEH and GSTM1 genotyping.

Inter-individual variation in metabolism of environmental toxicants, which is attributed to genetic polymorphism, may be a major risk factor in determining who will develop adverse health effects. This priority research area is the focus of many laboratories, and new techniques need to be developed to enhance the efficiency in generating data. We have developed and validated a new multiplex-polymerase chain reaction (PCR), restriction fragment length polymorphism (RFLP) procedure for simultaneous genotyping of cytochrome P450 II E1 (CYP2E1), microsomal epoxide hydrolase (mEH), and glutathione S-transferase mu (GSTM1). Enzymes from these three polymorphic genes are involved with the phase I and II metabolism of a variety of environmental toxicants. Therefore, simultaneous characterization of these genes will not only reduce costs but will increase the efficiency of data collection, thereby contributing to health risk assessment efforts.

Cytochrome P-450 CYP2E1↗
PubMed1980

Restoration of elbow flexion in arthrogryposis multiplex congenita.

In 15 patients with arthrogryposis multiplex congenita, 18 operations were performed to improve elbow function. These operations were for seven cases of pectoralis transfer, seven cases of anterior transfer of triceps, two cases of posterior elbow release, and two cases of Steindler flexoroplasty. Results were evaluated on two simple criteria: single-hand feeding and improved elbow joint motion. These criteria showed that the pectoralis transfer was the most effective procedure.

Arthrogryposis↗
PubMed2003

[Diagnosis of imported malaria with multiplex PCR on LighCycler apparatus].

For the diagnosis of imported malaria, a competitive multiplex PCR using LightCycler was developed and compared for 3 months with a traditional PCR method. Hundred eighty three patients were tested by these 2 techniques of molecular diagnosis: 60 were positive for P. falciparum, 9 were positive for other Plasmodium species and 114 were negative. The LightCycler method was found in total agreement with the traditional PCR.

Animals↗
PubMed2000

Validation of a reverse transcriptase multiplex PCR test for the serotype determination of U.S. isolates of bluetongue virus.

Bluetongue (BT) is an arthropod-borne viral disease affecting ruminants primarily in tropical and temperate regions of the world. Of the 24 serotypes of BT virus (BTV) identified worldwide, five have been found in the United States. Serotype identification of BTV isolates is important to the epidemiology of the virus, but current methods are cumbersome. A single-tube multiplex reverse transcriptase polymerase chain reaction (mRT-PCR) assay, previously developed for the serotype determination of U.S. BTV isolates, was evaluated. The determination of serotype was based on the size of the resultant amplified product. The procedure was evaluated using all 24 serotypes of BTV and nine serotypes of epizootic hemorrhagic disease virus (EHDV), a closely related orbivirus. Only the five U.S. serotypes of BTV were detected by the mRT-PCR. The assay was further tested using 132 BTV isolates originating from 24 western and southern states of the United States, from several different host species, spanning a period of 24 years. The serotypes of the isolates were determined by both a virus neutralization (VN) procedure and the mRT-PCR. Comparison of the mRT-PCR to the standard VN showed that the mRT-PCR successfully identified the serotypes of 130 of the isolates and was shown to be more reliable and specific than the VN assay.

Animals↗
PubMed2000

Multiplex-PCR-based differentiation and characterization of Candida-isolates derived from tortoises (Testudinidae).

Candida isolates (n=23) derived from Testudinidae were investigated by multiplex-polymerase chain reaction (PCR). The isolates comprised 13 Candida (C.) tropicalis, nine C. albicans and one C. parapsilosis. In addition, five reference strains C. albicans (ATCC 10231), C. tropicalis (DSM 4238), C. parapsilosis (DSM 4237), C. glabrata (ATCC 70614) and C. krusei (ATCC 70075) were investigated. PCR revealed easily distinguishable species-specific amplicons of the chs1-gene and resulted in a clear identification in all cases. No discrepancies between conventional identification techniques and the PCR-based system were seen. The described PCR offers a rapid alternative to conventional techniques for the identification of C. albicans, C. glabrata, C. tropicalis, C. parapsilosis and C. krusei.

Animals↗
PubMed2001

Detection of feline calicivirus, feline herpesvirus 1 and Chlamydia psittaci mucosal swabs by multiplex RT-PCR/PCR.

A single tube, multiplex reverse transcription (RT)-polymerase chain reaction (PCR)/PCR assay was developed for detection of feline herpesvirus 1 (FHV1), Chlamydia psittaci and feline calicivirus (FCV) in cats with upper respiratory tract disease (URTD), incorporating a simple, rapid extraction procedure capable of extracting both DNA and RNA. The assay was found to be as sensitive in vitro as simplex assays that have previously been shown to be as sensitive as, or more sensitive than, culture for each pathogen in experimentally infected cats. Conjunctival alone or both conjunctival and oropharyngeal swabs were collected from cats in 104 households with URTD. FHV1 was detected in 18 (17.3%) and C. psittaci was detected in 12 (11.5%) households. The prevalence of C. psittaci was not significantly different to that determined using a duplex PCR assay for C. psittaci and FHV1. The prevalence of FCV was affected by sample storage temperature. Of samples stored at -70 degrees C, 0/31 were positive for FCV but FCV was detected in 10/73 (13.7%) samples stored at 4 degrees C (P=0.006). Of the samples stored at 4 degrees C, 3/19 (15.8%) conjunctival swabs were positive for FCV and 6/32 (18.8%) oropharyngeal/conjunctival swabs were positive for FCV (P=0.79). The potential utility of restriction endonuclease analysis of RT-PCR products resulting from amplification of the hypervariable region of the capsid protein gene of FCV in field samples, without prior cultivation, was also examined. The assay may have considerable importance for diagnosis and epidemiological surveys of feline upper respiratory tract pathogens.

Animals↗
PubMed2002

A multiplex PCR for the detection of Brucella spp. and Leptospira spp. DNA from aborted bovine fetuses.

Bovine brucellosis and leptospirosis are important causes of bovine abortion around the world. Both diseases can be serologically diagnosed, but many factors may cause false positive and negative results. Direct methods based on bacteriological isolation are usually employed, but they are difficult, time consuming and dangerous. Monoplex polymerase chain reaction (PCR) have been successfully described for the detection of Brucella spp. and Leptospira spp. Aiming at improvement in the direct diagnosis, a multiplex PCR (mPCR) for the detection of these agents in aborted bovine fetuses is described. The detection threshold of the mPCR was evaluated in experimentally contaminated bovine clinical samples using a conventional proteinase K/SDS or a boiling-based extraction protocols. The mPCR was applied to two groups of clinical samples: 63 episodes of bovine abortion and eight hamsters experimentally infected with Leptospira interrogans serovar pomona. Adopting microbiological isolation as reference, the test showed a sensitivity of 100% in both groups of clinical samples. Seven samples collected from bovine fetuses were Brucella spp. culture negative but showed positive results in mPCR. Regarding Leptospira spp. detection, similar results were observed in three bovine clinical samples. All hamsters infected with Leptospira were positive in both microbiological culture and mPCR. The boiling extraction protocol showed better results in some clinical samples, probably by the removal of PCR inhibitors by heat treatment. The high sensitivity, simplicity and the possibility of detection of both bacteria in a single tube reaction support the use of the mPCR described in the routine diagnosis.

Abortion, Veterinary↗
PubMed2003

Detection of enterohemorrhagic Escherichia coli O157:H7 by using a multiplex real-time PCR assay for genes encoding intimin and Shiga toxins.

A multiplex real-time PCR (R-PCR) assay was designed and evaluated on the ABI 7700 sequence detection system (TaqMan) to detect enterohemorrhagic Escherichia coli (EHEC) O157:H7 in pure cultures, feces, and tissues. Three sets of primers and fluorogenic probes were used for amplification and real-time detection of a 106-bp region of the eae gene encoding EHEC O157:H7-specific intimin, and 150-bp and 200-bp segments of genes stx1 and stx2 encoding Shiga toxins 1 and 2, respectively. Analysis of 67 bacterial strains demonstrated that the R-PCR assay successfully distinguished EHEC O157:H7 serotype from non-O157 serotypes and provided accurate profiling of genes encoding intimin and Shiga toxins. Bacterial strains lacking these genes were not detected with this assay. The detection range of the R-PCR assay for the three genes was linear over DNA concentrations corresponding from 10(3) to 10(8)CFU/ml of EHEC O157:H7. The R-PCR allowed construction of standard curves that facilitated quantification of EHEC O157:H7 in feces and intestinal tissues. Detection sensitivity of the R-PCR assay ranged from 10(4) to 10(8)CFU/g of feces or tissues without enrichment. Enrichment of feces in a non-selective broth for 4 and 16h resulted in the detection of levels (from 10(0) to 10(3)CFU/g of feces) considered sufficient for infection in humans. The R-PCR assay for eae(O157:H7), stx1, and stx2 proved to be a rapid test for detection of EHEC O157:H7 in complex biological matrices and could also potentially be used for quantification of EHEC O157:H7 in foods or fecal samples.

Adhesins, Bacterial↗
PubMed2004

Diagnostic multiplex PCR for toxin genotyping of Clostridium perfringens isolates.

In this study we provide a protocol for genotyping Clostridium perfringens with a new multiplex PCR. This PCR enables reliable and specific detection of the toxin genes cpa, cpb, etx, iap, cpe and cpb2 from heat lysed bacterial suspensions. The efficiency of the protocol was demonstrated by typing C. perfringens reference strains and isolates from veterinary bacteriological routine diagnostic specimens.

Animals↗
PubMed1998

Multiplex PCR assay for detection of Clostridium perfringens in feces and intestinal contents of pigs and in swine feed.

A multiplex polymerase chain reaction (PCR) assay, developed to detect the alpha-toxin and enterotoxin genes (cpa and cpe, respectively) of Clostridium perfringens, was used to identify enterotoxigenic isolates of this organism from feces and intestinal contents of pigs and from feed samples from pig farms in Iowa. The organism was grown on tryptose-sulfite-cycloserine (TSC) agar, TSC agar without egg-yolk, sheep blood agar, or in brain heart infusion broth or cooked meat medium. DNA was extracted by boiling and the PCR assay was carried out using reagents from a commercial kit. The 319 bp amplification product of cpa and the 364 bp product of cpe were visualized under UV light after electrophoresis in a 2% agarose gel containing ethidium bromide. The average sensitivity of the assay, determined on artificially contaminated feces, was 9.2 x 10(4) colony forming units per gram. Assay of 97 isolates from feces and intestinal contents revealed cpa in 89, but all were negative for cpe. While 28% of the 442 total samples cultured yielded C. perfringens, only 5% of 298 fecal or intestinal contents samples were positive upon direct examination by the PCR assay. Ninety-one and eight-tenths % of isolates with the phenotype of C. perfringens were cpa positive by PCR. Forty-three percent of feed samples were culture positive, while 48.3% were PCR positive for cpa. None of these were cpe positive. We conclude that PCR is a useful assay for rapid detection of C. perfringens in feed, and for confirmation of the identity of isolates presumed to be C. perfringens.

Animal Feed↗
PubMed2001

Simultaneous measurement of antibodies to three HIV-1 antigens in newborn dried blood-spot specimens using a multiplexed microsphere-based immunoassay.

We developed a fluorescent immunoassay to simultaneously measure antibodies to three HIV-1 antigens from newborn dried blood-spot specimens. The multiplexed assay uses fluorescent microspheres and a flow analyzer. The procedure is sensitive, precise and accurate, and can be expanded to simultaneously measure additional multiple analytes from a single specimen.

Acquired Immunodeficiency Syndrome↗