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Biomedical subjects

C H Collins

Publications and source records attributed to C H Collins.

16 recordsLinked to original sources

Safe biotechnology (4). Recommendations for safety levels for biotechnological operations with microorganisms that cause diseases in plants.

The Working Party on Safety in Biotechnology of the European Federation of Biotechnology has proposed a classification of microorganisms that cause diseases in plants. In this paper appropriate safety levels are proposed for these classes of microorganisms in order to ensure that research, development and industrial fermentation work with plant pathogens will limit the risk of outbreaks of diseases in crops that could result from work with such microorganisms when they are cultivated in laboratories, glasshouses and biotechnology installations.

Containment of Biohazards

A comparison of APACHE II and a clinical sickness score. A study of 97 consecutive admissions to a district general hospital intensive care unit.

The aim of this study was to compare the predictive power of a simple illness severity score (Clinical Sickness Score) to that of APACHE II in a District General Hospital intensive therapy unit. A prospective comparison was carried out on 97 consecutive adult patients whose severity of illness was scored one hour after admission using both the Clinical Sickness Score and APACHE II. Intensive Therapy Unit and hospital outcomes were recorded for each patient. The Clinical Sickness Score and APACHE II identified survivors and nonsurvivors with similar power (p less than 0.001). There was a highly significant correlation between the two scoring systems for hospital survivors and nonsurvivors together (r = 0.5418, r2 = 0.28, p = less than 0.0001) and for hospital survivors alone (r = 0.6102, r2 = 0.37, p = 0.0001). Correlation for hospital nonsurvivors was not significant (r = 0.1629, r2 = 0.027, p = 0.3134). The positive predictive values of APACHE II were between 5% and 10% more sensitive than the Clinical Sickness Score for hospital outcome. Admission Clinical Sickness Score and APACHE II scores had similar predictive power in this study.

Adult

Treatment and disposal of clinical and laboratory waste.

There are no entirely satisfactory definitions of clinical waste; nor are there methods in general use that are safe and environmentally acceptable for the storage, transport and final disposal of the ever-increasing volume of such waste that is generated by the health services. Hazardous, potentially infectious and aesthetically objectionable waste has been found on beaches and exposed on domestic refuse landfill sites, causing public disquiet about health hazards and environmental pollution. Landfill is officially discouraged, where not illegal, and many older-type incinerators can not now be used because their effluent pollutes the atmosphere. Modern and efficient incinerators are expensive and the parochial nature of health service management and accounting mitigates against their installation and use. Laboratory waste, however, can be rendered safe and unobjectionable, aesthetically and environmentally, if the requirements and recommendations of the several Codes of Practice and technical advice, which are simple and inexpensive, are implemented by laboratory and hospital managers.

Hazardous Waste

Protocol for increasing organ donation after cerebrovascular deaths in a district general hospital.

In a district general hospital serving 303,000 people, deaths from cerebrovascular incidents over 12 months were analysed retrospectively. 8 patients who died in general wards were identified as potential organ donors. A working party then devised a protocol for managing such donors by transfer to the intensive care unit for support until organ retrieval could be arranged. In the first 19 months with the protocol, organs (1 heart, 2 sets of heart valves, 2 livers, and 16 kidneys) were retrieved from 8 patients who would not otherwise have become donors. If these results were replicated nationally a further 16.7 donors per million per year would be added to the current annual UK rate of 14.6 donors per million.

Adult

Hydroxylamine sensitivity and salt tolerance in screening and identifying mycobacteria.

Hydroxylamine sensitivity offered no advantage over p-nitrobenzoic acid in distinguishing between tubercle bacilli and other (opportunist and non-significant) mycobacteria. It was of limited use in identification procedures. Salt tolerance assisted in the identification of strains which may be Mycobacterium triviale and M. chelonei var borstelense.

Bacteriological Techniques

Identification of tubercle bacilli.

Initial screening of tubercle bacilli with 2-thiophene carboxylic acid hydrazide (TCH) or 2-furoic acid hydrazide (FAH) separates them into two groups. Resistant strains are Mycobacterium tuberculosis. Sensitive strains include M. tuberculosis, M. bovis and BCG which are separated by nitratase and oxygen requirement tests. Pyrazinamide sensitivity tests allow M. bovis and M. africanum to be identified. The niacin test is not used. Most strains of M. tuberculosis from Europeans are resistant to TCH and FAH and are in phage groups A and B, while most strains from Asians are sensitive and are in phage group I.

Bacteriological Techniques

Comparison of strains of Mycobacterium tuberculosis from British, Ugandan and Asian immigrant patients: a study in bacteriophage typing, susceptibility to hydrogen peroxide and sensitivity to thiophen-2-carbonic acid hydrazide.

Strains of Mycobacterium tuberculosis were obtained from 65 patients with pulmonary tuberculosis resident in Uganda, and from pulmonary and extrapulmonary tuberculosis in 42 British patients of European ethnic stock and in 67 Asian immigrants, often from Uganda, resident in Britain. The bacteriophage-type patterns of the African, British and Asian strains were different. The pattern for the Asian strains resembled that found previously in patients from South India, suggesting that there has been little interchange of organisms between the Asian community and the African and British communities alongside whom they have lived. The patterns for pulmonary and extra-pulmonary tuberculosis were similar. Strains of bacteriophage type 1, mainly obtained from Asians, were characterized by a greater susceptibility to the bactericidal activity of hydrogen-peroxide and/or a greater sensitivity to thiophen-2-carbonic acid hydrazide than strains of other types.

Asia

Bacteriophage typing of Mycobacterium tuberculosis strains isolated in South East England.

The species Mycobacterium tuberculosis may be subdivided by its susceptibility to lysis by bacteriophages. In this study 300 strains have been typed with six phages to determine the prevalence of various phage types in South East England. The distribution of the phage types is considered in relation to the patients' racial origins and the clinical presentation of disease, whether pulmonary or extrapulmonary. The technical aspects of phage typing are described and modifications of existing techniques are discussed.

Bacteriophage Typing

Subacute necrotizing encephalopathy (Leigh's disease): two unusual cases.

Two unusual cases of subacute necrotizing encephalopathy are described. In one, a marked hirsutism led to a suspicion of adrenal tumor or other endocrinopathy. In the other case, there was an agenesis of the corpus callosum, the second instance in which a malformation of the corpus callosum was associated with this condition. Electron micrographs from a case of Leigh's disease showed examples of marked axonal swelling and occasional splitting of the lamellae of the myelin sheath, probably responsible for the spongy state seen under light microscopy. That such marked changes were not seen in the "internal control" tended to exclude postmortem changes. The ultrastructure and histologic structure of striated muscle appeared normal in the one case examined.

Agenesis of Corpus Callosum