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Screening for large rearrangements of the BRCA1 gene in German breast or ovarian cancer families using semi-quantitative multiplex PCR method.

Since the identification of the breast and ovarian cancer susceptibility genes BRCA1 and BRCA2, a large number of different germline mutations in both genes have been found by conventional PCR-based mutation detection methods. Complex germline rearrangements such as those reported in the BRCA1 gene are often not detectable by these standard diagnostic techniques. To detect large deletions or duplications encompassing one or more exons of the BRCA1 gene and in order to estimate the frequency of BRCA1 rearrangements in German breast or ovarian cancer families, a semi-quantitative multiplex PCR method was developed and applied to DNA samples of patients from families negatively tested for disease causing mutations in the BRCA1 and BRCA2 coding regions by direct sequencing. Out of 59 families analysed, one family was found to carry a rearrangement in the BRCA1 gene (duplication of exon 13). The results indicate that the semi-quantitative multiplex PCR method is useful for the detection of large rearrangements in the BRCA1 gene and therefore represents an additional valuable tool for mutation analysis of BRCA1 and BRCA2.

Adult↗

A multiplex PCR method for the detection of all five individual genes of ica locus in Staphylococcus epidermidis. A survey on 400 clinical isolates from prosthesis-associated infections.

In Staphylococcus epidermidis, ica locus encodes for the synthesis of a polysaccharide intercellular adhesin (slime or biofilm). A multiplex polymerase chain reaction (PCR) for the detection of the five individual genes of ica locus was developed, with the aim to probe the set of genes in a large collection of Staphylococcus epidermidis clinical isolates. Single representative fragments for icaR, icaA, icaD, icaB, and icaC genes were selected. Multiplex PCR was applied to two reference Staphylococcus epidermidis strains [the non-biofilm-forming ATCC 12228 and the biofilm-forming ATCC 35984 (RP62A)] and to 400 clinical isolates of Staphylococcus epidermidis from orthopedic prosthesis associated infections. The gene profile was compared with the phenotypic biofilm-forming ability, evaluated by means of an optimized Congo red agar (CRA) plate test. Among the clinical isolates, 228 (57%) turned out completely ica positive and were biofilm producing. Among the 172 non-biofilm-forming strains (43%), 164 (41%) were completely ica negative and 8 strains (2%) harbored all five ica genes. The ica locus thus proves to be a cluster of strictly linked genes, without any evidence of single gene deletion.

Biofilms↗

A new multiplex assay allowing simultaneous detection of the inhibition of cell proliferation and induction of cell death.

The efficacy of distinct anti-cancer drugs used in the chemotherapy of human malignancies varies between tumor tissues and depends largely on the ability of the therapeutic agents to simultaneously inhibit cell proliferation and to eliminate malignant cells by apoptosis. Especially, detection of early apoptotic changes seems to be important because early stages of apoptosis differ from those of necrosis. Therefore, the development of a novel test allowing fast and concomitant screening of the anti-proliferative and pro-apoptotic action of a number of anti-cancer drugs is of great interest. For this purpose, we choose as an experimental model a well characterized anti-proliferative and pro-apoptotic effect of cisplatin (CP) on human cervical carcinoma HeLaS3 cells. As previously reported, exposure of HeLaS3 to CP resulted in a concomitant inhibition of cell proliferation and induction of apoptosis in a dose- and time-dependent manner. In the present study we performed two independent approaches. In the first approach, we examined the cell proliferation and activity of caspases-3/7 in two separate microtiter plates using the CellTiter-Glo Luminescent Cell Viability Assay and the Caspase-Glo 3/7 Assay, respectively. In the second approach, we determined the same parameters sequentially in one microtiter plate by a mutiplexing assay using CellTiter-Blue Cell Viability Assay and Caspase-Glo 3/7 Assay. The both approaches gave very similar results indicating that this new multiplexing assay offers an important advantage for simultaneous detection of cell number and activation of caspases-3/7. The new multiplexing assay offers a range of benefits over standard assays.

Antineoplastic Agents↗

Real-time nested multiplex PCR for the detection of herpes simplex virus types 1 and 2 and varicella zoster virus.

One hundred forty-nine specimens were tested in a LightCycler nested multiplex polymerase chain reaction (LCnmPCR) for Herpes simplex virus (HSV)1, HSV2, and VZV. Eighty-one were from genitourinary medicine (GUM) patients and the other 68 specimens were from other patients with skin lesions. The results were compared to a conventional multiplex nested PCR (nmPCR) using agarose gel electrophoresis. Twenty-five specimens were positive in both assays for HSV1 and 29 were positive for VZV. For HSV2 there were 27 positive in the LCnmPCR and 26 positive in the nmPCR assay. The melting temperatures (Tms) of each target were different with a mean of 84.75 degrees C for HSV1, 88.57 degrees C for HSV2, and 83.62 degrees C for VZV. The melting curves of positive specimens directly overlaid the melting curves of the positive controls in the assay. The LCnmPCR assay is a convenient alternative to conventional PCR using agarose gel electrophoresis. It improves specimen turnaround time by eliminating the need for gel electrophoresis, transillumination, and gel photography. It also shows increased sensitivity for HSV2 over our standard assay. This LCnmPCR reduces further the possibility of amplicon contamination with nested PCR protocols.

Base Sequence↗

Type-specific identification of human adenovirus 3, 7, and 21 by a multiplex PCR assay.

Human adenovirus (Ad) serotypes 3, 7, and 21 of DNA cluster B:1 are often associated with severe respiratory illness, particularly in infants and young children and, in addition to Ad4, are among the most important causes of acute respiratory disease syndrome in new military recruits. To address the inherent problems associated with classic typing methods, we developed a multiplex PCR assay for the rapid, specific identification of Ad3, Ad7, and Ad21 field isolates. To design type-specific primers for our assay, we sequenced the Ad21 hexon gene and compared this sequence with previously published sequences of Ad3, Ad7, and Ad16. The overall nucleotide (nt) and amino acid (aa) identities between Ad21 and Ad3, Ad7, and Ad16 were similar (ranges 78.3-80.8% nt; 84.1-86.2% aa), with significantly greater variability in the regions of the hexon that encode surface loops 1 and 2. Type-specific primers designed to the hypervariable regions correctly identified Ad3, Ad7, and Ad21 prototype strains and 53 previously typed Ad field isolates. No cross-reactions with other Ad serotypes were identified. Our multiplex PCR assay for type-specific identification of Ad3, Ad7, and Ad21 isolates will provide a rapid and convenient tool for the epidemiologic investigation of Ad-associated respiratory illness.

Adenoviridae↗

Validation and long-term assessment of an approach for the high throughput determination of lipophilicity (log POW) values using multiplexed, absorbance-based capillary electrophoresis.

A critical evaluation of the use of 96-capillary multiplexed microemulsion electrokinetic chromatography (MMEEKC) for the indirect determination of octanol-water partition coefficients (log POW values) for a wide range of structurally different compounds is presented. The various components of the microemulsion solution were evaluated and optimized for use in a multiplexed capillary format. A six-component calibration mixture and 23 different solutes (n = 4 each) were analyzed simultaneously, providing a throughput of up to 46 samples/h, which translates to greater than a 20-fold improvement over existing indirect log POW methods. Agreement to within +/-0.5 log P units of literature values was obtained for 51 of the 54 tested neutral and basic (uncharged) solutes. A linear free energy relationship (LFER) analysis performed on the MMEEKC system supports its use as a viable and effective model of the classical shake-flask method for log POW determinations. Moreover, a standard deviation of 0.1 or less log P units was obtained for 35 of 36 solutes analyzed repeatedly over an 8-month time period, documenting the long-term effectiveness of the analysis format. Critical comparisons between the proposed MMEEKC method and existing separation methods for the indirect determination of log POW values are also made. Overall, the results indicate that 96-capillary MMEEKC can serve as a high throughput, cost effective and robust approach and as a valid model for log POW determinations.

Algorithms↗

Multiplex RT-PCR assay for the detection of major fusion transcripts in Taiwanese children with B-lineage acute lymphoblastic leukemia.

BACKGROUND: The classification of B-lineage acute lymphoblastic leukemia (ALL) by specific chromosomal translocations may have prognostic implications. Reverse transcriptase-polymerase chain reaction (RT-PCR) assay is a useful tool for the detection of fusion transcript resulting from specific chromosomal translocation of the leukemic cells. In general, fusion transcripts are determined individually, a process which is labor intensive in order to detect all major fusion transcripts. PROCEDURE: We use a multiplex RT-PCR assay to detect both the CML- and ALL-type BCR-ABL transcripts of the t(9;22), all described variants of the E2A-PBX1 transcripts of t(1;19), the MLL-AF4 transcripts of t(4;11), and all described variants of TEL-AML1 (also termed ETV6-CBFA2) of the cryptic t(12;21) in 165 leukemic samples at diagnosis. RESULTS: The study yielded a completely concordant result with those obtained by the individual RT-PCR assay. In this cohort of Taiwan children, the relative frequencies of the four translocations of B-lineage ALL were as following: 6% with ALL-type t(9;22)/BCR-ABL, 7% t(1;19)/E2A-PBX1, 3% t(4;11)/MLL-AF4, and 18% t(12;21)/TEL-AML1, comparable to those in the Western countries. CONCLUSION: Multiplex RT-PCR assay is an efficient, sensitive, accurate, and cost-effective diagnostic tool, which will likely improve our ability in accurately and rapidly risk-stratifying children with ALL.

Adolescent↗

Time-multiplexed multislice inversion-recovery techniques for NMR imaging.

Multislice imaging techniques effectively applicable to inversion-recovery (IR) imaging are developed and applied to human imaging. These new multislice IR imaging sequences employ the time-multiplexing (TM) technique conventionally used in the slice-by-slice saturation-recovery (SR) imaging. Two new time-multiplexed multislice (TMM) IR imaging sequences are proposed and some of the experimental results obtained with the methods are presented.

Humans↗

Optimizing the efficiency of high-field multivoxel spectroscopic imaging by multiplexing in space and time.

A new strategy to yield information from the maximum number of voxels, each at the optimum signal-to-noise ratio (SNR) per unit time, in MR spectroscopic imaging (MRSI) is introduced. In the past, maximum acquisition duty-cycle was obtained by multiplexing in time several single slices each repetition time (TR), while optimal SNR was achieved by encoding the entire volume of interest (VOI) each TR. We show that optimal SNR and acquisition efficiency can both be achieved simultaneously by multiplexing in space and time several slabs of several slices, each. Since coverage of common VOIs in 3D proton MRSI in the human brain typically requires eight or more slices, at 3 T or higher magnetic fields, two or more slabs can fit into the optimum TR (approximately 1.6 s). Since typically four or less slices would then fit into each slab, Hadamard encoding is favored in that direction for slice profile reasons. It is demonstrated that per fixed examination length, the new method gives, at 3 T, twice as many voxels, each of the same SNR and size, compared with current 3D chemical shift imaging techniques. It is shown that this gain will increase for more extensive spatial coverage or higher fields.

Brain↗

Mononeuropathy multiplex (AAEE case report #11).

Mononeuropathy multiplex is a syndrome of diverse causes, the most common of which is nerve ischemia due to microangiopathy associated with diabetes or the collagen-vascular diseases. The acquired inflammatory demyelinating neuropathies invariably are multifocal, although the clinical manifestations of these and other multifocal neuropathies may appear symmetrical. The identification of multifocal neuropathies is important because of the frequent therapeutic implications. A case of mononeuropathy multiplex associated with polyarteritis nodosa is described.

Action Potentials↗

Case-of-the-month: perineuritis presenting as mononeuritis multiplex.

Perineuritis unassociated with other significant pathological changes is a rare finding. A patient is described with mild, non-insulin dependent diabetes mellitus who presented with the clinical picture of mononeuritis multiplex, and in whom perineuritis but no occlusive vascular disease was found on sural nerve biopsy. Treatment with prednisone and plasma exchange resulted in some improvement. We conclude that the focal perineuritis, rather than the diabetes, was responsible for the clinical picture mimicking mononeuritis multiplex. In conjunction with previous reports, this suggests that perineuritis may be a treatable neuropathy.

Aged↗

Prenatal diagnosis of Pelizaeus-Merzbacher disease: detection of proteolipid protein gene duplication by quantitative fluorescent multiplex PCR.

A prenatal diagnosis of Pelizaeus-Merzbacher disease (PMD) resulting from proteolipid protein gene (PLP) duplication was performed by a quantitative fluorescent multiplex PCR method. PLP gene copy number was determined in the proband, the pregnant mother, the male fetus and two aunts. Small amounts of genomic DNA extracted from peripheral blood and from chorionic villi were used. The fetus, in common with the proband, was identified as PMD-affected being a carrier of the PLP gene duplication, inherited from the mother, while the two aunts were non-carriers. The data obtained were confirmed by segregation analysis of a PLP-associated dinucleotide-repeat polymorphism amplified by the same multiplex PCR.

Case-Control Studies↗

Prenatal diagnosis of mos46,X,del(Y)(q11.2)/45,X by cytogenetic and molecular studies with multiplex STR analysis.

OBJECTIVES: To present the prenatal diagnosis of a fetus of mos46,X,del(Y)(q11.2)/45,X by cytogenetic and molecular analysis. CASE AND METHODS: A 35-year-old pregnant woman came to our hospital for amniocentesis, and fetal chromosomal aberrations with mos46,X, + mar/45,X were found. Fluorescence in situ hybridization revealed the existence of a Y centromere on the marker chromosome. Analysis with six pairs of short tandem repeat markers showed that the genomic DNA extracted from the uncultured amniotic fluid cells contained a deletion of Yq11.1-Yq11.2. Spermatogenesis loci of the Y chromosome were studied using four sets of multiplex PCR. The proximal two markers DYS271 and KALY were present and the other 16 distal markers were deleted. No deletion was noted in the Y chromosome of the father. RESULTS: Cytogenetic and molecular analyses revealed deletions of AZFb, d, and c regions on Yq11.2-Yqter in the fetal Y chromosome. Postmortem examination of the fetus showed a grossly normal male fetus with normal external genitalia and testes. CONCLUSION: The present report demonstrates that molecular analysis using polymorphic microsatellite markers and multiplex PCR is a useful complement to cytogenetic methods for the identification and the characterization of Y-chromosomal deletions.

Adult↗

High-content proteomics: fluorescence multiplexing using an integrated, high-sensitivity, multiwavelength charge-coupled device imaging system.

The detection of proteins in 2-D gels and their subsequent identification by MS is still the "gold standard" in proteomics. Fluorescent detection has increasingly replaced colorimetric and radiometric detection on gels and blots. The reasons for this are multiple and varied and include higher sensitivity, better quantitation, increased dynamic range, speed, safety and ease of use. Unlike other methods, fluorescent protein detection is also typically very consistent in response from protein to protein and in many cases is compatible with MS methods for protein identification. The superior sensitivity and benefits achieved by fluorescent techniques have spurred the development of instrumentation capable of delivering precise, sensitive, high-resolution image acquisition over a wide variety of excitation and emission wavelengths. This report focuses on applications using the highly sensitive, charge-coupled device based ProXPRESS multilabel imager, readily configurable for image acquisition over a wide variety of wavelengths (380-700 nm and ultraviolet (UV)) using xenon lamp or UV excitation. The ability to simultaneously detect enzyme activities or protein modifications with different color fluorescent probes in addition to total protein amounts (multiplexing) allows the further mining of proteomic data content from a single set of protein samples. To this end, the development of instrumentation that enables a multiplexing strategy will become central to in-depth proteomic studies. The ProXPRESS maximizes the efficiency of experimental strategies that require flexibility and multicolor fluorescence detection.

Electrophoresis, Gel, Two-Dimensional↗

Multiplex proteomic analysis by two-dimensional differential in-gel electrophoresis.

This paper describes the use of fluorescence two-dimensional differential in-gel electrophoresis in a multiplex analysis of two distinct proteomes. As a model system, cerebral cortex tissues were analyzed from neurokinin1 receptor knockout (NK(1)R-/-) and wild type (NK(1)R+/+) mice in an attempt to identify molecular pathways involved in the function of this protein. Paired NK(1)R-/- and NK(1)R+/+ samples were labeled with fluorescent Cy3 and Cy5 dyes and electrophoresed on the same two-dimensional gels. Scanning the gels at wavelengths specific for each dye revealed the two different proteomes which were overlaid and the differences in abundance of specific protein spots were determined by the Amersham Biosciences DeCyder Differential In-gel Analysis software. A Cy2-labeled sample pool was co-electrophoresed with all Cy3- and Cy5-labeled sample pairs as an internal standard providing a link for inter-gel comparisons and for more robust statistical analysis of the data. Eight spots were found to be upregulated and two downregulated in the NK(1)R-/- mice compared to NK(1)R+/+ controls. Matrix assisted laser desorption/ionisation-time of flight (MALDI-TOF) mass fingerprinting was used to identify the proteins. The results illustrate the power of this multiplex proteomics technology and illustrate how proteomics can be used to understand gene function.

Animals↗

Multiplexed fluorescence detection of phosphorylation, glycosylation, and total protein in the proteomic analysis of breast cancer refractoriness.

The Multiplexed Proteomics (MP) technology is a new approach that permits quantitative, multicolor fluorescence detection of proteins in one-dimensional or two-dimensional gels. This methodology allows for multiplexed identification and differential analysis of phosphoproteins, glycoproteins, and total proteins within a single gel electrophoresis experiment. Here the MP system was applied to the differential proteomic analysis of pregnancy-induced refractoriness to breast cancer using a rat model system. Differential analyses identified multiple proteins with altered phosphorylation, glycosylation, or protein expression patterns.

Animals↗

Screening for proteolytic activities in snake venom by means of a multiplexing electrospray ionization mass spectrometry assay scheme.

A multiplexed mass spectrometry based assay scheme for the simultaneous determination of five different substrate/product pairs was developed as a tool for screening of proteolytic activities in snake venom fractions from Bothrops moojeni. The assay scheme was employed in the functional characterization of eight model proteases. Time-resolved reaction profiles were generated and the relative reaction progress at each time point was determined. These were used to semi-quantitatively sort the catalytic activities of each enzyme towards the respective substrates into six classes. The resulting activity pattern served as an activity fingerprint for each enzyme. The multiplex assay scheme was then applied to a screening for proteolytic activities in fractions of the pre-separated venom from B. moojeni. Activity patterns of each fraction were generated and used to sort the fractions into three different categories of activity. By comparison of the fingerprint activity patterns of the venom fractions and the model enzymes, a compound with proteolytic properties similar to activated protein C was detected.

Animals↗

Further evidence that arthrogryposis multiplex congenita in the human sometimes is caused by an intrauterine vascular accident.

A 7 1/2-year-old girl with arthrogryposis multiplex congenita of the amyoplasia type in association with intestinal atresias, gastroschisis, Möbius anomaly, and hypoplasia of the pectoral, biceps, and deltoid muscles is described. Several combinations of these birth defects have been previously described. There is considerable evidence that gastroschisis, intestinal atresia, Poland sequence, and Möbius anomaly each has a vascular pathogenesis. Based on the associations seen in this child and past reports of more limited, similar cooccurrences, we suggest that arthrogryposis multiplex congenita may sometimes be caused by an intrauterine vascular catastrophe.

Abdominal Muscles↗