Phage antibodies: new technology to obtain monoclonal antibodies to the multidrug-resistance gene product P-glycoprotein.
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ATP Binding Cassette Transporter, Subfamily B, Mem↗
Biomedical subjects
C Cunningham
Publications and source records attributed to C Cunningham.
Hepatitis A transmission by factor IX concentrates.
Factor IX concentrates unlike factor VIII concentrates have not to date been associated with the transmission of hepatitis A virus (HAV). A retrospective study by reverse transcriptase polymerase chain reaction on a batch of factor IX concentrate used to treat two haemophilia B patients who developed jaundice and IgM anti-HAV antibodies within 50 days of factor IX administration in 1985 revealed the presence of HAV RNA. These findings indicate that factor IX concentrates can transmit HAV and that appropriate viral inactivation steps to inactivate nonenveloped viruses as well as enveloped viruses are necessary to ensure the safety of factor IX concentrates.
Adult↗
Cloning of a cellulase gene from the rumen anaerobe Fibrobacter succinogenes SD35 and partial characterization of the gene product.
A gene encoding an enzyme which degrades cellulose (end-1) was isolated from a library of Fibrobacter succinogenes SD35 DNA fragments and expressed in pUC18. The product of end-1 showed significant activity against carboxymethylcellulose but relatively minor activity against lichenan, xylan and avicel. The nucleotide sequence indicated a product of 388 amino acids with a molecular mass of 50.2 kDa. This was in agreement with the molecular size estimated by gel electrophoresis. No significant DNA sequence similarity was identified with any published endoglucanase.
Amino Acid Sequence↗
Injury surveillance at a national multi-sport event.
The 1994 Australian Universities Games represents a multi-sport event which featured 5106 participants competing in nineteen sports. Injury surveillance was conducted by means of the injury Surveillance Form, which recorded time, mechanism, site, type and severity of injury, as well as initial treatment and referral patterns. Over six days of competition, 1177 presentations with injury were recorded, sustained by 994 athletes or 19.5% of all participating athletes. Tae kwon do and hockey were the sports with the greatest incidence of injury. Haematomas, muscle strains and ligament sprains were the most common injuries, with contact and overuse the most common mechanisms of injury. Mild injuries dominated and severe injuries were uncommon. 75% of injuries were initially assessed and treated by a nurse, first aid officer or sports trainer; 15% by a physiotherapist and 10% by a doctor. The authors' recommendation is that such a team of medical staff should be an integral part of any large sporting event, whether participants are professionals or amateurs. Additionally, they need to be supported by facilities and services such as central clinics, a nearby x-ray centre, a nearby hospital and an ambulance/first aid transport network.
Adolescent↗
A new factor from Escherichia coli affects translocation of mRNA.
Reconstitution of protein synthesis from purified translation factors on ribosomes from Escherichia coli has revealed the requirement for a protein, W, that affects chain elongation and is essential to reconstitute the process (Ganoza, M. C., Cunningham, C., and Green, R. M. (1985) Proc. Natl. Acad. Sci. U.S.A. 82, 1648-1652). We report that W has no effect on initiation complex formation by 30 or 70 S ribosomes or on the association of ribosomal subunits, peptide bond synthesis, or binding Ala-tRNA, which is the second amino acid of the coat protein of the MS2 RNA virion. W has a pronounced effect on tripeptide synthesis, and is obligatory for the synthesis of the coat protein or of the hexapeptide encoded by f2am3 RNA. Extracts from a temperature-sensitive mutant of the translocase, EF-G, were purified free of the W protein and were used to score for translocation defects. W is required for binding Ser-tRNA, the third N-terminal amino acid of the MS2 or f2 RNA coat protein to ribosomes bearing fMet-Ala-tRNA, as well as for the ejection of deacyl-tRNA from ribosomes, which occurred concomitant with the binding of the Ser-tRNA. We propose that W functions by ejecting tRNAs from ribosomes in a step that precedes the movement of mRNA during translocation.
Bacterial Proteins↗
Expression and purification strategies for the production of single-chain antibody and T-cell receptor fragments in E. coli.
This work describes protocols for the production of single-chain antibody and T-cell receptor fragments in E. coli. A choice of methods is given for the purification of the recombinant fragments that rely on the use of either immunoaffinity or metal chelate affinity chromatography. The TCR fragments may have to be denatured and refolded before the fragments attain their proper conformation.
Chromatography, Affinity↗
Determination of aluminium in serum, dialysate fluid and water by inductively coupled plasma optical emission spectrometry.
Methods for the determination of aluminium in serum, dialysate fluid and water by inductively coupled plasma optical emission spectrometry are described and validated. Aluminium was measured at 167 nm using an argon purged monochromator. Matrix effects in serum and dialysate fluid were overcome by using an yttrium internal standard. Serum was found to have a complicated background in the region of 167 nm: careful selection of the wavelength used for background correction is therefore a pre-requisite for accurate analysis. The method for serum was validated by comparison with electrothermal atomization atomic spectrometry and the limit of agreement determined to be +/- 0.3 mumol/L. Routine performance in a quality assessment scheme has been highly satisfactory for a period of 1 year. The method is ideal for fast and accurate monitoring of patients potentially at risk from aluminium toxicity.
Aluminum↗
Dietary protein and growth in infants with chronic renal insufficiency: a report from the Southwest Pediatric Nephrology Study Group and the University of California, San Francisco.
This report describes growth and nutrition data from the feasibility phase of a clinical trial that was designed to evaluate the effect of diet protein modification in infants with chronic renal insufficiency (CRI). The purpose of the proposed trial was to compare the safety (effect on growth in length) and efficacy [effect on glomerular filtration rate (GFR)] of a diet with a low protein: energy (P:E) ratio versus a control diet in such patients. Twenty-four infants with GFRs less than 55 ml/min per 1.73 m2 were randomly assigned at 8 months of age to receive either a low-protein (P:E ratio 5.6%) or control protein (P:E ratio 10.4%) formula, which resulted in average protein intakes of 1.4 and 2.4 g/kg per day in the low and control groups, respectively. Overall energy intakes over a 10-month period of study averaged 92% +/- 12% recommended dietary allowance (RDA) for length in the low-protein group and 92 +/- 15% RDA in the control group. Weight for age standard deviation scores (SDS) were comparably low in both groups at the time of randomization (low-protein--2.0 +/- 1.3, control -1.9 +/- 1.1) and at the end of the study (low -1.9 +/- 1.2, control -1.7 +/- 0.9). Length for age SDS at entry tended to be lower in the low-protein group but were not significantly different in the two groups (low -2.2 +/- 1.4 vs. control -1.7 +/- 1.4). However, at 18 months the low-protein group had a significantly lower SDS for length (-2.6 +/- 1.2 vs. -1.7 +/- 1.4).(ABSTRACT TRUNCATED AT 250 WORDS)
Academic Medical Centers↗
Detection of Eber-1 RNA in primary brain lymphomas in immunocompetent and immunocompromised patients.
Tissue from primary central nervous system lymphoma (PCNSL) which developed in five patients with acquired immuno deficiency syndrome (AIDS), nine patients without immunodeficiency, and two Epstein-Barr virus (EBV)-positive control cell lines (B95-8 and Raji) were examined for the presence of EBER-1 RNA. The tissues were hybridized with digoxigenin-labeled sense or anti-sense EBER-1 riboprobes. In all five AIDS-related PCNSLs, strong hybridization signals were found with the EBER-1 anti-sense probe. Signals could be eliminated by preincubation of the tissues with RNase-A. Hybridization with the EBER-1 sense probe showed no signal. All PCNSLs from immunocompetent patients (five paraffin-embedded, four frozen) showed no hybridization signals with EBER-1 sense or antisense probe but good hybridization signals with probes to immunoglobulin kappa or lambda light chain indicating RNA preservation. The paraffin-embedded B95-8-positive control cell-line showed positive hybridization in most cells with the anti-sense EBER-1 probe, and up to one percent of the cells had a weak signal with the sense probe. Most Raji cells showed a uniform signal with the anti-sense EBER-1 probe only. We conclude that, PCNSLs that arise in AIDS patients are associated with latent EBV infections, whereas PCNSLs from immunocompetent patients are not indicating a probable role for EBV in pathogenesis of these tumors.
Acquired Immunodeficiency Syndrome↗
Spontaneous assembly of bivalent single chain antibody fragments in Escherichia coli.
The ability of immunoglobulin Fab and single chain (ScFv) fragments to penetrate effectively into tissue from the vascular system has made these molecules excellent candidates as drug delivery systems and imaging tools. This study investigates the use of single chain antibody fragment bacterial expression vectors as a possible strategy for the production of these molecules. We have modified the pSW1-VHD1.3-VKD1.3-TAG1 vector [Ward et al. (1989) Nature 341, 544-546] which originally, when expressed in E. coli, produced an Fab fragment. In an effort to improve the affinity of the parent vector product a novel single chain antibody construct which encodes a protein with anti-P. aeruginosa activity was generated using a 14 amino acid linker [Chaudhary et al. (1990) Proc. natn. Acad. Sci. U.S.A. 87, 1066-1070]. In addition to the heavy and light chain variable domain genes, our construct also contained the light chain kappa constant domain gene to aid purification of the fragments. To underline this difference from the conventional ScFv fragment we have described this protein as a ScAb. The ScAb generated had an antigen binding capacity similar to the parent anti-P. aeruginosa antibody but was superior to the recombinant anti-P. aeruginosa Fab fragment. On HPLC and non-denaturing gel electrophoresis analysis, the ScAb was found to exist in multimeric forms while the Fab fragment existed only as a single unit. Dimeric ScAb had a similar antigen binding profile to the parent antibody.
Antibodies↗
Deletion analysis of chromosome 8p in sporadic colorectal adenomas.
In order to assess the stage of colorectal tumorigenesis at which chromosome 8p loss of heterozygosity (LOH) occurs, 56 sporadic adenomas were examined for LOH at four polymorphic loci which show frequent LOH in carcinomas. LOH was found in only 5 out of 51 (9.8%) informative adenomas, whereas studies with the same markers in 85 informative carcinomas showed a LOH of 45%. The adenomas showing LOH were all in the 'high-risk' clinicopathological category, being 10 mm or more in diameter and showing tubulovillous architecture. It is concluded that the chromosome 8p locus is involved preferentially in the development of carcinomas rather than adenomas.
Adenoma↗
Candidal sepsis and meningitis in a very-low-birth-weight infant successfully treated with fluconazole and flucytosine.
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Candidiasis↗
Genetics of colorectal cancer.
Recent advances in understanding the genetic basis of malignant disease have been dominated by research in colorectal cancer. In familial adenomatous polyposis, characterisation of the causative gene had immediate clinical relevance allowing confident prediction of disease inheritance. Somatic mutations in this gene have been demonstrated to have a fundamental role in the development of sporadic colorectal cancer. More recently, efforts have focused on the genetic abnormalities responsible for hereditary non-polyposis colorectal cancer which may possibly account for up to 15% of all colorectal malignancies. In the foreseeable future, it is possible that significant population-based genetic screening for this condition will be available. As the molecular basis of colorectal cancer is elucidated, it will inevitably lead to radical changes in clinical management, particularly with the possible introduction of gene therapy and chemoprevention. This review discusses the current developments in colorectal cancer genetics which will be central to such changes.
Adenomatous Polyposis Coli↗
X linked mental retardation with non-deletional alpha thalassaemia (ATR-X): further delineation of the phenotype.
Two sibs with non-deletional alpha thalassaemia and mental retardation (ATR-X) have been ascertained showing variable neurological features. The proband had a complex neurological picture with recurrent apnoea, complex partial seizures, and prolonged periods of semiconsciousness between 12 and 17 months of age. Episodes of spontaneous laughter were also a feature. An EEG was initially normal. Hb H inclusions were present but rare in this family. The sole genital anomaly was deficiency of the foreskin, a feature not previously described in ATR-X.
Abnormalities, Multiple↗
A cosmid-based system for constructing mutants of herpes simplex virus type 1.
Cosmids containing large fragments of herpes simplex virus type 1 DNA were prepared using a vector that allows intact inserts to be excised using the restriction endonuclease PacI. Two independent sets (A and B) of five cosmids were identified whose inserts overlap and represent the entire viral genome, and set C was obtained by replacing two cosmids in set B. Each set gave rise to viral plaques when digested with PacI and transfected into cells in culture. Two cosmids common to sets B and C ostensibly contain one of the origins of viral DNA replication (oriL) in a region of overlap between inserts, but both actually consist of a minority of apparently intact (ori+L) forms and a majority of deleted (ori-L) forms. These sets yielded exclusively ori+L viral progeny. When either of these cosmids was replaced by a derivative comprising only ori-L forms, ori+L and ori-L progeny were obtained, and only ori-L progeny were produced when both were replaced. One cosmid in set A contains the oriL locus in a nonoverlapping region and lacks ori+L forms. This set generated only ori-L virus. Viral mutants with lesions in either or both of genes UL2 and UL44, which are not essential for growth in cell culture, were constructed using cosmids containing specifically introduced frameshift mutations. A mutant with a frameshift mutation in an essential gene (UL33) was isolated by transfecting a complementing cell line. These results indicate that a cosmid-based system will facilitate isolation of large numbers of defined viral mutants.
Animals↗
Multidrug resistance during cancer chemotherapy--biotechnological solutions to a clinical problem.
Tumour cells can be resistant to a variety of chemotherapeutic drugs of different structure (multidrug resistance) by expressing a transmembrane pump (P-glycoprotein) on their cell surface. This situation can lead to a failure of cancer chemotherapy as the P-glycoprotein acts by actively pumping the drugs out of cells, thus lowering the intracellular concentration of the drug and, hence, its cytotoxic effectiveness. This review summarizes present and proposed approaches to preventing or circumventing the action of this drug-transporting protein.
Biotechnology↗
Partial subclavian steal.
The phenomenon of subclavian steal syndrome has recently been found to have a subset group that has been described as partial or "pre-steal" in physiology. Our case of a Marine Corps pilot with this partial subclavian steal physiology is reviewed, in addition to the maneuvers we performed to temporarily convert him to complete steal physiology. A discussion of the symptomatology and prognosis of this diagnosis is included, with emphasis on military service.
Adult↗
Deletion mapping in colorectal cancer of a putative tumour suppressor gene in 8p22-p21.3.
Although previous studies of acquired loss of heterozygosity (LOH) in colorectal tumours have suggested that a tumour suppressor gene may lie within the short arm of chromosome 8, its precise localisation remains to be determined. To obtain a more accurate positional map 120 colorectal cancers were examined with eight chromosome 8 polymorphic markers comprising both restriction fragment length polymorphisms and microsatellite polymorphisms based on (CA)n repeats. 91 cases were informative and LOH was detected in 47 (51%). The markers most commonly sited within the lost region mapped to the lipoprotein lipase gene (LPL) at chromosome 8p22. From study of tumours showing break-points within 8p, a common region of deletion was established extending centromerically from LPL to the ankyrin 1 gene (ANK1) which is mapped to 8p21.1-11.2. This overlaps with common deleted regions observed in other studies of colorectal tumours (8p23.1-p21.3) and bladder tumours (8p21-q11.2). Taken together, the results in colorectal cancer delineate a region in 8p22-p21.3 where the putative tumour suppressor gene must lie. The chromosome 8p deletions appear to be independent of those involving 5q and 17p in the same tumours. No relationship was found between the presence of 8p deletion and site or stage of the tumour, or the sex or age of the patient at diagnosis.
Animals↗