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Biomedical subjects

G Fung

Publications and source records attributed to G Fung.

7 recordsLinked to original sources

Chorioamnionitis and outcome in extremely preterm infants.

INTRODUCTION: Chorioamnionitis is a risk factor for preterm delivery. Intrauterine infection leads to the fetal inflammatory response which is characterised by elevated cytokine levels. Chorioamnionitis is reported to cause accelerated but abnormal lung maturation, resulting in decreased incidence of respiratory distress syndrome (RDS) but increased chronic lung disease (CLD), and predisposes the infant to cerebral injury. OBJECTIVE: To investigate the relation between chorioamnionitis and RDS, CLD, cerebral lesions, neurodevelopmental outcome and mortality in a cohort of extremely premature infants. MATERIALS AND METHODS: Infants born between 1997 and 2001 with a gestational age of less than 28 weeks or a birth weight of less than 1000 g were divided into two groups: Group 1 with evidence of chorioamnionitis and Group 2 without. Outcomes of these two groups of infants were compared. RESULTS: A total of 388 infants were included (105 in Group 1 and 283 in Group 2). Chorioamnionitis was significantly associated with an increased risk of extreme preterm delivery. Group 1 showed a trend towards an increased incidence of CLD and mortality, while the incidence of periventricular leukomalacia, retinopathy of prematurity (ROP) and necrotising enterocolitis (NEC) were similar between the two groups. Subgroup analysis of 2-year neurodevelopmental outcome showed an increased trend towards cerebral palsy and visual impairment, while the incidence of developmental delay and hearing impairment are similar between the two groups. CONCLUSION: Extremely preterm infants with chorioamnionitis showed a trend towards an increased incidence of CLD, mortality, cerebral palsy and visual impairement, but a decreased risk of RDS.

Chorioamnionitis↗

Simple, quick and efficient site-directed antibody immobilization in a cartridge.

A method is described for the simple, quick and efficient attachment of antibody within a cartridge for use as an immunoaffinity chromatography column. Antibodies are immobilized via their Fc regions through the use of periodate-oxidized carbohydrate functionalities of the immunoglobulin G. The method allows for the in situ coupling of the immunoglobulin G without prior removal of the oxidizing periodate solution. The entire procedure can be completed in 50 minutes. This method is especially useful for quick determinations of a particular monoclonal antibody's functionality or avidity towards a specific antigen. It may also be used in place of a conventional immunoaffinity column for the rapid isolation of small amounts of an antigen. This method will reduce the lengthy process of preparing an immunoaffinity column from several days to less than an hour.

Antibodies↗

Isolated sphenoiditis: a diagnostic problem.

A case of primary isolated sphenoiditis that developed cavernous sinus thrombosis is presented. It is difficult to diagnose and patients are often not seen initially by an ENT surgeon, making it more important for other branches of medicine to be aware of this condition. We discuss isolated sphenoiditis with particular reference to the diagnosis, management and complications of this condition.

Cavernous Sinus↗

Enzyme immunoassay for the quantitation of immunoglobulin M class antibodies to Salmonella minnesota R595 and Escherichia coli J5 lipopolysaccharides.

The level of human immunoglobulin (IgM) in plasma specific for the lipopolysaccharide of Salmonella minnesota R595 (R595 LPS) and Escherichia coli J5 (J5 LPS) was quantitated by an enzyme immunoassay (EIA) in which purified antigen is adsorbed directly onto polystyrene-acrylic copolymer cuvettes. Highly purified anti-J5 and R595 LPS specific IgM prepared by ion-exchange resin, gel filtration, and affinity resin chromatography were used as standards. The levels of specific IgM were determined in 200 plasma samples obtained from normal donors. Anti-R595 IgM levels varied from less than 30 micrograms/ml (91%), from 30 to 100 micrograms/ml (8.5%), and greater than 100 micrograms/ml (0.5%). Anti-J5 IgM levels in 68% of the donor plasmas were less than or equal to 5 micrograms/ml. The levels in 30.5% of the donor plasmas ranged from 6 to 100 micrograms/ml; the remaining 1.5% had greater than 100 micrograms/ml anti-J5 IgM. Specific IgM levels in four lots of normal pooled plasma each consisting of about 10,000 L averaged 12.7 micrograms/ml and 13.3 micrograms/ml for R595 and J5, respectively. The assay was modified to quantitate rabbit plasma as well. For this purpose, the EIA has been performed on microtiter plates, and the core LPS was fixed onto the wells by chemical treatment with glutaraldehyde which results in higher stability and retention of the antigen in the wells. Specificity of the EIA was demonstrated by the absence of significant cross reactivity between R595 IgM and J5 LPS and between J5 IgM and R595 LPS, furthermore, we only observed partial adsorption (approximately 25%-33%) of the R595 and J5 IgM by Pseudomonas aeruginosa LPS, a wild type endotoxin. The described quantitative assay is useful for both scientific studies and clinical investigations.

Antibodies, Bacterial↗

Extraction of an intravascularized pacemaker lead--a new approach to an unusual problem.

A new catheter approach to removing an intravascularized, nonfunctional pacemaker lead which was fixed at both distal (right ventricular endocardium) and proximal (brachiocephalic vein/superior vena cava) ends is described. This case also emphasizes the need for removal of an old pacemaker lead that caused bacteremia in a patient with a prosthetic aortic valve even when infection was presumed to be cured.

Aged↗

Characterization of chemical and enzymatic acid-labile phosphorylation of histone H4 using phosphorus-31 nuclear magnetic resonance.

Phosphorus-31 nuclear magnetic resonance (31P NMR) is used to investigate acid-labile phosphorylation of histone H4. 31P NMR detects phosphorylated histidine residues in in vitro enzymatically phosphorylated H4. The source of kinase is nuclei from either regenerating rat liver or Walker-256 carcinosarcoma. When regenerating rat liver is the source, 31P NMR spectroscopy on the denatured phosphorylated protein exhibits a resonance at 5.3 ppm relative to an 85% orthophosphoric acid external reference. This peak corresponds well with the chemical shift of standard pi-phosphohistidine scanned under similar conditions. Sodium dodecyl sulfate (NaDodSO4)--polyacrylamide gel electrophoresis confirms acid lability. When the source of kinase is Walker-256 carcinosarcoma, the 31P NMR spectrum contains a resonance at 4.9 ppm which corresponds well with standard tau-phosphohistidine run under the same conditions. Chemical phosphorylation of H4 has been accomplished by using dipotassium phosphoramidate which specifically phosphorylated the imidazole moiety of histidine at neutral pH. NaDodSO4--polyacrylamide gel electrophoresis confirms acid lability, and high-pressure liquid chromatography of protein hydrolysates yields phosphohistidine. 31P NMR of chemically phosphorylated H4 in a structured state reveals two peaks at 4.8 and 7.3 ppm with line widths of 9 and 55 Hz, respectively. These resonances indicate that both histidine residues of H4 (His-18 and His-75) are phosphorylated, the latter relatively immobile and the former relatively free in solution. 31P NMR studies on chemically phosphorylated peptide fragments of H4, namely, H4(1-23) and H4(38-102), confirm this model of H4 structure.

Animals↗