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Biomedical subjects

D C Cameron

Publications and source records attributed to D C Cameron.

At least 55 records · Page 3Linked to original sources
PubMed1978

Radiographic patterns of pulmonary involvement in acute mycoplasmal infections.

The radiological appearances and the progress of the pulmonary manifestations of serologically-proven acute Mycoplasma pneumoniae infection were studied in 29 patients. The radiological changes seen at and after admission were not helpful in establishing an aetiological diagnosis except in three patients, in whom a "classical" pattern of mycoplasma pneumonia, based on the radiological appearnaces at different histopathological stages of the disease, could be recognised retrospectively. The patterns seen were varied and generally non-specific, and were not related to the age of the patient or to the duration of disease prior to admission. Specific anti-mycoplasma therapy may have prevented the progress of the disease after admission, although five of six patients in whom radiological deterioration occurred after admission were receiving such treatment.

Acute Disease↗
PubMed1977

The radiographic patterns of acute mycoplasma pneumonitis.

Twenty-two cases of serologically proven pulmonary mycoplasma infection have been reviewed. All showed abnormality on plain chest radiographs. A definitive diagnosis could not be made on initial or individual films. However, studies of sequential films enabled diagnostic patterns to be distinguished.

Adolescent↗
PubMed1970

Drug dependence: some research issues.

This paper examines some problems of drug dependence, stressing the importance of a balanced approach. Consideration must be given to the demand for, as well as the supply of, drugs. Without a demand, there would be no continuing supply of man-made agents and no need to control the availability of naturally occurring agents.To achieve a balanced approach, increased research is needed into the effects on man of taking various dependence-producing drugs (particularly when these are used for long periods of time), the natural history of drug taking, the relative effectiveness of various preventive, therapeutic and restorative approaches and techniques, and means of identifying substances that, because of their dependence-producing properties, are apt to induce individual or public health problems. Attention is also called to some problems that may inhibit, but do not preclude, the initiation of studies in the field of drug dependence.

Journal Article↗
PubMedDate not supplied

Cellular and metabolic engineering. An overview.

Metabolic engineering is defined as the purposeful modification of intermediary metabolism using recombinant DNA techniques. Cellular engineering, a more inclusive term, is defined as the purposeful modification of cell properties using the same techniques. Examples of cellular and metabolic engineering are divided into five categories: 1. Improved production of chemicals already produced by the host organism; 2. Extended substrate range for growth and product formation; 3. Addition of new catabolic activities for degradation of toxic chemicals; 4. Production of chemicals new to the host organism; and 5. Modification of cell properties. Over 100 examples of cellular and metabolic engineering are summarized. Several molecular biological, analytical chemistry, and mathematical and computational tools of relevance to cellular and metabolic engineering are reviewed. The importance of host selection and gene selection is emphasized. Finally, some future directions and emerging areas are presented.

Bacteria↗
PubMedDate not supplied

Enhanced production of (R)-1,2-propanediol by metabolically engineered Escherichia coli.

1,2-Propanediol (1,2-PD) is a major commodity chemical currently derived from propylene. Previously, we have demonstrated the production of enantiomerically pure (R)-1,2-propanediol from glucose by an engineered E. coli expressing genes for NADH-linked glycerol dehydrogenase and methylglyoxal synthase. In this work, we investigate three methods to improve 1,2-PD in E. coli. First, we investigated improving the host by eliminating production of a byproduct, lactate. To do this, we constructed strains with mutations in two enzymes involved in lactate production, lactate dehydrogenase and glyoxalase I. (Surprisingly, when mutations were made in its ability to produce lactate, one strain of E. coli [MM294], produced a small amount of 1,2-PD without any added genes.) Second, we constructed a complete pathway to 1,2-PD from the glycolytic intermediate, dihydroxyacetone phosphate. Our previous 1, 2-PD producing strains relied on at least one endogenous E. coli activity and only produced 0.7 g/L of 1,2-PD. The complete pathway involved the coexpression of methylglyoxal synthase (mgs), glycerol dehydrogenase (gldA), and either yeast alcohol dehydrogenase (adhI) or E. coli 1,2-propanediol oxidoreductase (fucO). Third, we investigated bioprocessing improvements by carrying out a fed-batch fermentation with the best engineered strain (expressing mgs, gldA, and fucO). A final titer of 4.5 g/L of (R)-1,2-PD was produced, with a final yield of 0.19 g of 1,2-PD per gram of glucose consumed. This work provides a basis for further strain and process improvement.

Escherichia coli↗