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Biomedical subjects

G J Cox

Publications and source records attributed to G J Cox.

At least 19 recordsLinked to original sources
PubMed2004

Quality of life following resection, free flap reconstruction and postoperative external beam radiotherapy for squamous cell carcinoma of the base of tongue.

This study was conducted to evaluate quality of life in a cohort of patients with squamous cell carcinoma of the tongue base, treated with primary surgery, reconstruction and postoperative radiotherapy. Twelve patients were assessed in a cross-sectional study using the University of Washington Quality of Life Instrument (UW-QOL). All patients underwent external beam irradiation following primary resection of their tumour and reconstruction. Patients on average reported their overall and health related QOL to be good. Functionally they had good pain control, speech intelligibility, activity and recreational levels. There were some limitations in chewing, swallowing and taste. The results suggest that surgical resection can offer good functional and overall QOL results for advanced tumours when combined with reconstruction. The morbidity associated with postoperative radiotherapy includes reduced swallowing, taste, saliva production and difficulty chewing.

Adult↗
PubMed2004

Effects of clinical service reorganisation on cellular pathology workload.

AIMS: To assess changes in volume and complexity of cellular pathology workload after clinical service reorganisation and alterations in pathology reporting practices, and to identify objective measures of change applicable to all cellular pathology departments. The ear, nose, and throat (ENT), head and neck (HN) specialty was chosen for assessment. METHODS: Cellular pathology workload from the ENT-HN surgical specialty was assessed numerically and the complexity in examination of cancer resection specimens was evaluated. Medical and technical time inputs in the reporting of ENT-HN cancer resections were measured prospectively, and the histological and cytological workload arising from the management of such cases was obtained. RESULTS: The 88.83% increase in ENT-HN specimens contrasted with a 13.53% increase in total surgical workload. Substantial increases in work complexity were found when measured as blocks/slides for each case and number of histochemical/immunohistochemical requests. On average, examination of one ENT-HN cancer case consumed 55% of one pathologist's work session and over one 10th of a technician's working week. On average, each cancer generated 3.3 histological and 1.06 cytological specimens. CONCLUSIONS: Evidence is provided of the increase in cellular pathology workload and in its complexity. This study lists objective measures of complexity applicable to all pathology subspecialties. Given the workforce crisis and expanding clinical needs, realistic workload calculations should include measurement of complexity and not just volumes.

England↗
PubMed2001

Carbonic anhydrase IX, an endogenous hypoxia marker, expression in head and neck squamous cell carcinoma and its relationship to hypoxia, necrosis, and microvessel density.

Carbonic anhydrase IX (CA IX) is a transmembrane glycoprotein with an active extracellular enzyme site. We have shown previously that it was hypoxia inducible and may therefore be an endogenous marker of hypoxia. It is overexpressed in some tumors, particularly renal cell carcinoma. The aim of this study was to examine the expression and localization of CA IX in head and neck squamous cell carcinoma (HNSCC) and relate this to the location of tumor microvessels, angiogenesis, necrosis, and stage. Expression of CA IX was determined by immunoblotting in three HNSCC cell lines grown in normoxia and hypoxia (pO(2) 0.1%) and three paired tumor and normal tissue samples of HNSCC. Archived paraffin sections (79) of HNSCC were immunostained with antibodies to CA IX and CD34 to determine microvessel density (MVD). By double staining sections with CA IX and CD34, the distance between blood vessels and the start of CA IX expression and necrosis was calculated. CA IX was induced by hypoxia in all three HNSCC cell lines and overexpressed in HNSCC tumor tissue. Overexpression was localized to the perinecrotic area of the tumor on immunostaining, and the percentage area of the tumor expressing CA IX was significantly higher with more tumor necrosis (P = 0.001), a high MVD (P = 0.02), and advanced stage (P = 0.033) on univariate analysis and necrosis (P = 0.0003) and MVD (P = 0.0019) on multivariate analysis. The median distance between a blood vessel and the start of CA IX expression was 80 microm (range, 40-140 microm). CA IX is overexpressed in HNSCC because of hypoxia and is a potential biomarker for hypoxia in this tumor. Overexpression may help to maintain the intracellular pH, giving tumor cells a survival advantage and enhancing resistance to radiotherapy and chemotherapy. CA IX is a potential target for future therapy in HNSCC.

Antigens, Neoplasm↗
PubMed2000

Vertical extended hemi crico-laryngectomy and reconstruction with a prefabricated tracheal free flap--initial results.

We describe our experiences of treating three patients with recurrent T3 squamous cell carcinoma of the larynx, following initial treatment with radiotherapy; using the technique of partial crico-laryngectomy and autologous pre-fabricated tracheal flap reconstruction as described in 1998 by Delaere (1). We have found the technique to be technically challenging. The patients require extensive speech and swallowing rehabilitation following surgery, but the functional result offers significant advantages over the other surgical salvage procedures of total or near-total laryngectomy. We describe our early results of three patients that we have treated using this technique.

Aged↗
PubMed1997

Polynucleotide vaccines in animals: enhancing and modulating responses.

We immunized cattle, the natural host for bovine herpesvirus 1 (BHV-1), with a polynucleotide vaccine encoding BHV-1 glycoprotein D. These cattle trials clearly indicate that large species can be immunized with polynucleotide vaccines. Recently, using a murine model, we demonstrated that: the cellular compartment to which the expressed antigen is delivered determines the type of immune response (type 1 or type 2), and that the magnitude and direction of the immune response can be modulated by coadministration of plasmid encoded cytokines and antigen. Finally, we demonstrated that immunization of mice with a polynucleotide vaccine encoding BHV-1 gD could circumvent preexisting passively transferred, gD specific, polyclonal antisera and lead to the development of an active immune response.

Animals↗
PubMed1995

Zinc-binding of the cysteine-rich domain encoded in the open reading frame of 1B of the RNA polymerase gene of coronavirus.

We cloned and sequenced the second open reading frame of the RNA polymerase gene, ORF1b, of bovine coronavirus. In the region representing nucleotide positions 4919-5677 upstream from the initiation codon of the 32K non-structural protein gene, we identified two putative functional domains. One of these domains contained four leucine residues repeated exactly in every seventh position, and the other domain represented a cluster of cysteine and histidine residues. The DNA sequence representing these domains was cloned and expressed in Escherichia coli as fusion proteins with glutathione S-transferase from Schistosoma japonicum. A high level expression of the cysteine-rich domain was achieved as a fusion protein when the bacterial culture was induced with IPTG. In a solid phase zinc binding assay using the recombinant fusion protein, we found that the protein containing the cysteine-rich domain was able to bind to radioactive zinc in vitro, demonstrating that the polypeptide encoded by the ORF1b of coronavirus is a zinc-binding protein.

Animals↗
PubMed1994

Etiology and outcome of diarrhea after marrow transplantation: a prospective study.

BACKGROUND/AIMS: Acute diarrhea after marrow transplant is usually ascribed to acute graft-vs.-host disease (GVHD) or infection, with a reported 40%-50% incidence of infection. The aim of this study was to determine the incidence of acute diarrhea after transplantation, its causes, and its outcome. METHODS: Two hundred ninety-six patients were followed up; patients with diarrhea were studied using standard evaluation of stool plus immunoelectron microscopy; assays for astrovirus, picobirnavirus, and Norwalk virus; and gene-probe methods for toxin-producing Escherichia coli. In 38 patients with diarrhea, intestinal biopsy specimens and duodenal fluid were also analyzed. RESULTS: One hundred fifty acute diarrheal episodes developed in 126 patients (an incidence of 43%). Intestinal infection was found in 20 of 150 episodes: viruses (astrovirus, adenovirus, cytomegalovirus, and rotavirus) in 12 patients, nosocomially acquired bacteria (Clostridium difficile and Aeromonas) in 7 patients, and mixed infection in 1 patient. Acute GVHD was responsible for 72 of 150 episodes (48%). Clinical signs and symptoms of infection and GVHD were similar. In 58 of 150 episodes (39%), no clear etiology could be found for self-limited diarrhea. CONCLUSIONS: Intestinal infection accounted for 13% and acute GVHD for 48% of diarrheal episodes. The most common infecting organisms were astrovirus, C. difficile, and adenovirus. Most cases of diarrhea after marrow transplant are not caused by infection.

Acute Disease↗
PubMed1993

Pilomatrixoma of the external auditory meatus.

Pilomatrixoma is a benign skin tumour arising from the outer hair root matrix. It is an uncommon tumour which favours the hair bearing area of the head and neck. The preauricular area is a well documented site, but to our knowledge, there are no reports of a pilomatrixoma arising in the external auditory meatus. We present such a case and discuss the historical background along with its pathological and clinical features.

Child↗
PubMed1993

Bovine herpesvirus 1: immune responses in mice and cattle injected with plasmid DNA.

Mice and cattle injected with plasmids encoding bovine herpesvirus 1 (BHV-1) glycoproteins developed gene-specific antibody responses capable of neutralizing BHV-1. The ability of animals to respond serologically to DNA injections was in part dependent on the quantity of DNA injected and was also negatively affected by carrier DNA. Calves injected with a plasmid encoding BHV-1 gIV developed significant antibody titers to gIV and shed less virus than did the control calf after challenge. This report indicates the potential of DNA injection as a method of vaccination.

Animals↗
PubMed1991

Structural analysis of the conformational domains involved in neutralization of bovine coronavirus using deletion mutants of the spike glycoprotein S1 subunit expressed by recombinant baculoviruses.

Two conformation-dependent neutralizing epitopes, A and B, have been mapped to the S1 subunit of the S spike glycoprotein of bovine coronavirus (BCV). In order to characterize the structure of these antigenic sites, we constructed a series of cDNA clones encoding deleted or truncated S1 derivatives and expressed the modified genes in insect cells using recombinant baculoviruses. Monoclonal antibodies directed against epitopes A and B recognized only the mutant S1 polypeptides containing amino acids 324-720, as demonstrated by immunoprecipitation and Western blot analysis in the absence of beta-mercaptoethanol. In addition, two domains within this region were identified and only mutants containing both domains were immunoreactive, indicating that both were critical in the formation of the antigenic determinants. One domain was localized between residues 324 and 403 and the other at residues 517-720. Deletion of either domain inhibited extracellular secretion of the mutant proteins whereas mutants containing both or none of the domains were secreted efficiently. This observation suggests a vital function of the native conformation of the S1 protein in both antigenic structure and intracellular transport. Antigenic determinants A and B were not distinguished, but these determinants appeared to require both domains for epitope formation. Our results suggest that the antigenic determinants formed by two domains are likely associated with the probable polymorphic region of the BCV S1 subunit.

Animals↗
PubMed1991

Bovine coronavirus nonstructural protein ns2 is a phosphoprotein.

To investigate the nature of the bovine coronavirus (BCV) ns2 protein, the gene encoding this protein was cloned and was expressed as a beta-galactosidase fusion protein. Antiserum raised against this protein reacted specifically with BCV-infected fixed cells in indirect immunofluorescence microscopy and precipitated an in vitro synthesized product approximately 32-kDa in molecular weight and an equivalent protein from BCV-infected cells. The synthesis of ns2 was found to be similar to the structural proteins of BCV and pulse-chase experiments indicated that ns2 protein was stable and that it accumulated in BCV-infected cells. Synthesis of ns2 in the presence of [32P] orthophosphate revealed that it is a phosphoprotein. Phosphoamino acid analysis confirmed the phosphorylated nature of ns2 and identified serine and threonine as its phosphorylated amino acid residues. This is the first demonstration of a phosphorylated nonstructural protein in coronavirus-infected cells.

Amino Acids↗