The paradoxes of genetically modified foods.
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Food Handling↗
Biomedical subjects
B Dixon
Publications and source records attributed to B Dixon.
A matter of life or death.
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Animal Rights↗
A divergent non-classical class I gene conserved in salmonids.
Complementary DNA for two class I genes of the rainbow trout, Oncorhynchus mykiss, were characterized. MhcOnmy-UBA*01 is similar to Onmy-UAC32 and the classical major histocompatibility complex class I genes of other fish species, whereas Onmy-UAA*01 is divergent from all class I genes so far characterized. Onmy-UAA*01 is expressed at lower levels than Onmy-UBA*01. Although Onmy-UAA*01 exhibits restriction fragment length polymorphism on Southern blotting, the encoded protein is highly conserved. Two allotypes, which differ only by substitution at amino acid position 223 of the alpha 3 domain, have been defined. Onmy-UAA*01 has an exon-intron organization like other class I genes and contains a Tc1-like transposon element in intron III. Orthologues of Onmy-UAA*01 have been characterized in four other species of salmonid. Between four species of Oncorhynchus, UAA*01 proteins differ by only 2-6 amino acids, whereas comparison of Oncorhynchus with Salmo trutta (brown trout) reveals 14-16 amino acid differences. The Onmy-UAA*01 gene has properties indicative of a particularly divergent non-classical class I gene.
Amino Acid Sequence↗
Proximal small bowel infarction associated with portal venous gas.
Clostridium perfiringens may cause myonecrosis (i.e. gas gangrene), acute food poisoning or necrotic enteritis (e.g. enteritis necroticans or Pig Bel). We describe a case of enteritis necroticans in a 33 year old man with acute myeloid leukaemia. He presented with an acute abdomen, diarrhoea and pancytopaenia and extensive accumulation of gas in the intrahepatic and extrahepatic portal veins. Despite urgent resuscitation he died shortly after arrival in the Intensive Care Unit. Treatment of enteritis necroticans requires urgent surgery to remove dead bowel and in adults intravenous penicillin (1g 2-hourly) and metronidazole (500 mg 8-hourly) or clindamycin (600 mg 6-hourly). While antibiotics may also reduce toxin formation, beta toxoid has not been found to be of benefit in established disease.
Journal Article↗
The right to a fair trial.
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Breast Neoplasms↗
The photodynamic response of two rodent tumour models to four zinc (II)-substituted phthalocyanines.
Four novel zinc (II)-substituted phthalocyanines, varying in charge and hydrophobicity, were evaluated in vivo as new photosensitizers for photodynamic therapy. Two rat tumours with differing vascularity were used: a mammary carcinoma (LMC1) and a fibrosarcoma (LSBD1), with vascular components six times higher in the latter (10.8%+/-1.5) than in the former (1.8%+/-1.4). Each sensitizer was assessed for tumour response relative to normal tissue damage, and optimum doses were selected for further study, ranging from 0.5 to 20 mg kg(-1). Interstitial illumination of the tumours was carried out using a 200-microm-core optical fibre with a 0.5 cm length of diffusing tip, at either 680 or 692 nm, depending on the sensitizer. Light doses of between 200 and 600 J were delivered at a rate of 100 mW from the 0.5-cm diffusing section of the fibre. Maximum mean growth delays ranged from 9 to 13.5 days depending on sensitizer and type of tumour, with the most potent photosensitizer appearing to be the cationic compound. Histopathological changes were investigated after treatment to determine the mechanism by which tumour necrosis was effected. The tumours had the appearance of an infarct and, under the conditions used, the observed damage was shown to be mainly due to ischaemic processes, although some direct tumour cell damage could not be ruled out.
Animals↗
CK-1, a putative chemokine of rainbow trout (Oncorhynchus mykiss).
Chemokines are small inducible proteins that direct the migration of leukocytes. While chemokines are well characterised in mammals, they have yet to be identified in fish. We have isolated a cDNA clone from rainbow trout (Oncorhynchus mykiss) which encodes a protein (CK-1) having structural features typical of chemokines. Amino-acid residues that define the beta-chemokines of mammals are conserved in CK-1, including the paired cysteine motif, CC. Further similarities are shared with the C6 subfamily of beta-chemokines. In contrast, the organisation of the CK-1 gene is closer to that of mammalian alpha-chemokine genes than beta-chemokine genes. The CK-1 gene is present in all four salmonid species examined and the nucleotide sequences of the exons are highly conserved. CK-1 has characteristics in common with mammalian alpha and beta-chemokine genes, suggesting that this salmonid chemokine gene preserves traits once present in the ancestral chemokine gene from which modern mammalian chemokine genes evolved.
Animals↗
Expression and temperature-dependent regulation of the beta2-microglobulin (Cyca-B2m) gene in a cold-blooded vertebrate, the common carp (Cyprinus carpio L.).
Expression of beta2-microglobulin (beta2m) in the common carp was studied using a polyclonal antibody raised against a recombinant protein obtained from eukaryotic expression of the Cyca-B2m gene. Beta2m is expressed on peripheral blood Ig+ and Ig lymphocytes, but not on erythrocytes and thrombocytes. In spleen and pronephros, dull- and bright-positive populations could be identified correlating with the presence of erythrocytes, thrombocytes, and mature leucocytes or immature and mature cells from the lympho-myeloid lineage, respectively. Thymocytes were shown to be comprised of a single bright-positive population. The Cyca-B2m polyclonal antiserum was used in conjunction with a similarly produced polyclonal antiserum to an MHC class I (Cyca-UA) alpha chain to investigate the expression of class I molecules on peripheral blood leucocytes (PBL) at different permissive temperatures. At 12 degrees C, a temporary downregulation of class I molecules was demonstrated, which recovered to normal levels within 3 days. However, at 6 degrees C, a lasting absence of class I cell-surface expression was observed, which could be restored slowly by transfer to 12 degrees C. The expression of immunoglobulin molecules on B cells was unaffected by temperature changes. The absence of the class I cell-surface expression was shown to be the result of a lack of sufficient Cyca-B2m gene transcription, although Cyca-UA mRNA was present at comparable levels at all temperatures. This suggests that class I expression is regulated by a temperature-sensitive transcription of the Cyca-B2m gene.
Animals↗
Planning and implementing an anesthesia crisis resource management course for student nurse anesthetists.
Development of Anesthesia Crisis Resource Management (ACRM) skills is a highly desirable outcome of a nurse anesthesia educational program. Access to an ACRM course is limited by a variety of factors including cost, availability of a center, time constraints, and the lack of adequately prepared CRNA faculty. The authors describe a Nurse Anesthesia Program's planning and implementation of an ACRM course by using a high fidelity human simulator. Key supportive and logistical elements necessary to implement an ACRM course are described. The authors address administrative concerns, faculty preparation needs, and explain the process of course design. Strengths of the course and problems encountered during the implementation of the experience are described. Feedback from participating students, faculty perceptions, and lessons learned from the experience are shared.
Clinical Competence↗
New and resurgent infections--new and future responses.
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Communicable Disease Control↗
Don't blame the messenger.
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Journal Article↗