Audit of acute hypoglycaemia in children: re-audit of procedures for diagnosis.

Background: A protocol exists for the collection of samples to investigate unexplained hypoglycaemia, termed the 'hypopack'. These packs are kept in Accident and Emergency departments and neonatal special care baby units throughout Northern Ireland and most wards of the Regional Children's Hospital. A retrospective audit of 107 hypopacks received between July 2001 and December 2003 highlighted a number of problems: samples collected when the patient was receiving dextrose, incomplete clinical history provided, insufficient and haemolysed samples received and poor filing of reports in charts.

Molecular diagnostics: future probe-based strategies.

Nucleic acid amplification technologies (NAATs) represent powerful tools in clinical microbiology, particularly in areas where traditional culture-based methods alone prove insufficient. A notable advantage is in reducing the time from taking samples to reporting results. This, and the specificity and sensitivity imparted by NAATs, can help to improve patient care.

Evaluation of an isothermal signal amplification method for rapid detection of methicillin-resistant Staphylococcus aureus from patient-screening swabs.

A new molecular assay (CytAMP) utilizing isothermal signal-mediated amplification of RNA was evaluated for rapid detection of methicillin (oxacillin)-resistant Staphylococcus aureus (MRSA). The assay targeted the coa (coagulase) and mecA genes, thereby simultaneously identifying S. aureus and methicillin (oxacillin) resistance.

Sequence-dependent folding of DNA three-way junctions.

Three-way DNA junctions can adopt several different conformers, which differ in the coaxial stacking of the arms. These structural variants are often dominated by one conformer, which is determined by the DNA sequence. In this study we have compared several three-way DNA junctions in order to assess how the arrangement of bases around the branch point affects the conformer distribution.

Use of signal-mediated amplification of RNA technology (SMART) to detect marine cyanophage DNA.

Here, we describe the application of an isothermal nucleic acid amplification assay, signal-mediated amplification of RNA technology (SMART), to detect DNA extracted from marine cyanophages known to infect unicellular cyanobacteria from the genus Synechococcus. The SMART assay is based on the target-dependent production of multiple copies of an RNA signal, which is measured by an enzyme-linked oligosorbent assay. SMART was able to detect both synthetic oligonucleotide targets and genomic cyanophage DNA using probes designed against the portal vertex gene (g20).

Specific detection of DNA and RNA targets using a novel isothermal nucleic acid amplification assay based on the formation of a three-way junction structure.

The formation of DNA three-way junction (3WJ) structures has been utilised to develop a novel isothermal nucleic acid amplification assay (SMART) for the detection of specific DNA or RNA targets. The assay consists of two oligonucleotide probes that hybridise to a specific target sequence and, only then, to each other forming a 3WJ structure. One probe (template for the RNA signal) contains a non-functional single-stranded T7 RNA polymerase promoter sequence.

An optimized set of human telomere clones for studying telomere integrity and architecture.

Telomere-specific clones are a valuable resource for the characterization of chromosomal rearrangements. We previously reported a first-generation set of human telomere probes consisting of 34 genomic clones, which were a known distance from the end of the chromosome ( approximately 300 kb), and 7 clones corresponding to the most distal markers on the integrated genetic/physical map (1p, 5p, 6p, 9p, 12p, 15q, and 20q). Subsequently, this resource has been optimized and completed: the size of the genomic clones has been expanded to a target size of 100-200 kb, which is optimal for use in genome-scanning methodologies, and additional probes for the remaining seven telomeres have been identified.

Development and clinical application of an innovative fluorescence in situ hybridization technique which detects submicroscopic rearrangements involving telomeres.

We report an innovative fluorescence in situ hybridization technique which exploits a unique resource of 41 telomere-specific probes and allows the simultaneous analysis of the subtelomeric region of every chromosome for deletion, triplication and balanced translocation events. This technique requires only a single microscope slide per patient and is expected to be a useful diagnostic tool with applications in the fields of idiopathic mental retardation, the detection of congenital abnormalities and in some forms of cancer. This will lead to more accurate genetic counselling of patients and their families and will provide the basis for future diagnostic, therapeutic and preventative measures.

Rapid determination of fetal sex in coelomic and amniotic fluid by fluorescence in situ hybridisation.

Coelomic fluid (n = 32), amniotic fluid (n = 26) and placental tissue were obtained from 32 women undergoing termination of pregnancy at 7-11 weeks of gestation. Fluorescence in situ hybridisation (FISH) was performed to determine fetal sex using a heterochromatic Y probe and an alpha satellite repeat probe for chromosome X. In each case there was concordance in the fetal sex from the three compartments.

Rapid detection of chromosome aneuploidies in fetal blood and chorionic villi by fluorescence in situ hybridisation.

Objective: Evaluation of fluorescence in situ hybridisation in the detection of numerical aberrations involving chromosomes X, Y, 13, 18 and 21.

Setting: Harris Birthright Research Centre for Fetal Medicine.

Subjects And Methods: Chorionic villi (n = 45) or fetal blood (n = 34) were obtained from 79 pregnancies undergoing fetal karyotyping at 10 to 39 weeks of gestation because of ultrasonographic markers of fetal chromosomal abnormality.

Trisomy 12 in B-cell chronic lymphocytic leukaemia: an evaluation of 33 patients by direct fluorescence in situ hybridization (FISH).

An adaptation of the standard fluorescence in situ hybridization (FISH) technique allowing rapid analysis (4 h) has been used to study the prevalence of trisomy 12 in 33 patients with B-CLL, of whom 54% have been shown to have this abnormality. The presence of trisomy 12 has been compared with clinical parameters, and there may be a relationship between the prevalence of trisomy 12 in B-CLL and duration of disease.

Coelocentesis: a new technique for early prenatal diagnosis.

Chorionic villus sampling and amniocentesis have disadvantages. In 100 women undergoing termination of pregnancy, coelomic fluid was successfully aspirated in 96% of cases at 6-10 weeks' gestation, 42% at 11, and 10% at 12 weeks. Cytogenetic analysis always failed with coelomic fluid, but fetal sexing was always successful with fluorescence in-situ hybridisation and polymerase chain reaction, and the results agreed with those obtained from chorionic villi and amniotic fluid in all cases.

Molecular analysis of the methane monooxygenase (MMO) gene cluster of Methylosinus trichosporium OB3b.

The oxidation of methane to methanol in methanotrophic bacteria is catalysed by the enzyme methane monooxygenase (MM0). This multicomponent enzyme catalyses a range of oxidations including that of aliphatic and aromatic compounds and therefore has potential for commercial exploitation. This study details the molecular characterization of the soluble MMO (sMMO) genes from the Type II methanotroph Methylosinus trichosporium OB3b.

The methane monooxygenase gene cluster of Methylosinus trichosporium: cloning and sequencing of the mmoC gene.

Methane monooxygenase (MMO) is the enzyme responsible for the conversion of methane to methanol in methanotrophic bacteria. The soluble MMO enzyme complex from Methylosinus trichosporium also oxidizes a wide range of aliphatic and aromatic compounds in a number of potentially useful biotransformations. In this study we have used heterologous DNA probes from the type X methanotroph Methylococcus capsulatus (Bath) to isolate mmo genes from the type II methanotroph M.

Cloning, sequencing and expression of the glutamine synthetase structural gene (glnA) from the obligate methanotroph Methylococcus capsulatus (Bath).

The structural gene (glnA) encoding the ammonia-assimulation enzyme glutamine synthetase (GS) has been cloned from the obligate methanotroph Methylococcus capsulatus (Bath). Complementation of Escherichia coli glnA mutants was demonstrated. In vitro expression analysis revealed that the cloned glnA gene coded for a polypeptide of apparent Mr 60,000, as determined by PAGE.